diff --git a/fairmq/DeviceRunner.h b/fairmq/DeviceRunner.h
index 2588d7cb..4f9931f2 100644
--- a/fairmq/DeviceRunner.h
+++ b/fairmq/DeviceRunner.h
@@ -19,8 +19,8 @@
 #include <string>
 #include <vector>
 
-namespace fair {
-namespace mq {
+namespace fair::mq
+{
 
 /**
  * @class DeviceRunner DeviceRunner.h <fairmq/DeviceRunner.h>
@@ -88,7 +88,6 @@ struct ModifyRawCmdLineArgs : Event<DeviceRunner&> {};
 struct InstantiateDevice : Event<DeviceRunner&> {};
 } /* namespace hooks */
 
-} /* namespace mq */
-} /* namespace fair */
+} // namespace fair::mq
 
 #endif /* FAIR_MQ_DEVICERUNNER_H */
diff --git a/fairmq/EventManager.h b/fairmq/EventManager.h
index d4b3380f..bb119d95 100644
--- a/fairmq/EventManager.h
+++ b/fairmq/EventManager.h
@@ -21,9 +21,7 @@
 #include <boost/functional/hash.hpp>
 #include <boost/signals2.hpp>
 
-namespace fair
-{
-namespace mq
+namespace fair::mq
 {
 
 // Inherit from this base event type to create custom event types
@@ -137,7 +135,6 @@ class EventManager
     }
 }; /* class EventManager */
 
-} /* namespace mq */
-} /* namespace fair */
+} // namespace fair::mq
 
 #endif /* FAIR_MQ_EVENTMANAGER_H */
diff --git a/fairmq/FairMQDevice.h b/fairmq/FairMQDevice.h
index 92ebb6fa..5d2eb010 100644
--- a/fairmq/FairMQDevice.h
+++ b/fairmq/FairMQDevice.h
@@ -41,13 +41,10 @@ using FairMQChannelMap = std::unordered_map<std::string, std::vector<FairMQChann
 using InputMsgCallback = std::function<bool(FairMQMessagePtr&, int)>;
 using InputMultipartCallback = std::function<bool(FairMQParts&, int)>;
 
-namespace fair
-{
-namespace mq
+namespace fair::mq
 {
 struct OngoingTransition : std::runtime_error { using std::runtime_error::runtime_error; };
 }
-}
 
 class FairMQDevice
 {
diff --git a/fairmq/FairMQMessage.h b/fairmq/FairMQMessage.h
index f9eacaa7..5a2ccd74 100644
--- a/fairmq/FairMQMessage.h
+++ b/fairmq/FairMQMessage.h
@@ -18,9 +18,7 @@
 using fairmq_free_fn = void(void* data, void* hint);
 class FairMQTransportFactory;
 
-namespace fair
-{
-namespace mq
+namespace fair::mq
 {
 
 struct Alignment
@@ -29,8 +27,7 @@ struct Alignment
     explicit operator size_t() const { return alignment; }
 };
 
-} /* namespace mq */
-} /* namespace fair */
+} // namespace fair::mq
 
 class FairMQMessage
 {
@@ -63,9 +60,7 @@ class FairMQMessage
 
 using FairMQMessagePtr = std::unique_ptr<FairMQMessage>;
 
-namespace fair
-{
-namespace mq
+namespace fair::mq
 {
 
 using Message = FairMQMessage;
@@ -73,7 +68,6 @@ using MessagePtr = FairMQMessagePtr;
 struct MessageError : std::runtime_error { using std::runtime_error::runtime_error; };
 struct MessageBadAlloc : std::runtime_error { using std::runtime_error::runtime_error; };
 
-} /* namespace mq */
-} /* namespace fair */
+} // namespace fair::mq
 
 #endif /* FAIRMQMESSAGE_H_ */
diff --git a/fairmq/FairMQPoller.h b/fairmq/FairMQPoller.h
index 1b41e19d..44bf924a 100644
--- a/fairmq/FairMQPoller.h
+++ b/fairmq/FairMQPoller.h
@@ -26,16 +26,13 @@ class FairMQPoller
 
 using FairMQPollerPtr = std::unique_ptr<FairMQPoller>;
 
-namespace fair
-{
-namespace mq
+namespace fair::mq
 {
 
 using Poller = FairMQPoller;
 using PollerPtr = FairMQPollerPtr;
 struct PollerError : std::runtime_error { using std::runtime_error::runtime_error; };
 
-} /* namespace mq */
-} /* namespace fair */
+} // namespace fair::mq
 
 #endif /* FAIRMQPOLLER_H_ */
diff --git a/fairmq/FairMQSocket.h b/fairmq/FairMQSocket.h
index f95dbe6a..3513523f 100644
--- a/fairmq/FairMQSocket.h
+++ b/fairmq/FairMQSocket.h
@@ -19,9 +19,7 @@
 
 class FairMQTransportFactory;
 
-namespace fair
-{
-namespace mq
+namespace fair::mq
 {
 
 enum class TransferCode : int
@@ -32,8 +30,7 @@ enum class TransferCode : int
     interrupted = -3
 };
 
-} // namespace mq
-} // namespace fair
+} // namespace fair::mq
 
 class FairMQSocket
 {
@@ -87,16 +84,13 @@ class FairMQSocket
 
 using FairMQSocketPtr = std::unique_ptr<FairMQSocket>;
 
-namespace fair
-{
-namespace mq
+namespace fair::mq
 {
 
 using Socket = FairMQSocket;
 using SocketPtr = FairMQSocketPtr;
 struct SocketError : std::runtime_error { using std::runtime_error::runtime_error; };
 
-} /* namespace mq */
-} /* namespace fair */
+} // namespace fair::mq
 
 #endif /* FAIRMQSOCKET_H_ */
diff --git a/fairmq/FairMQTransportFactory.h b/fairmq/FairMQTransportFactory.h
index ee896b1a..a53484df 100644
--- a/fairmq/FairMQTransportFactory.h
+++ b/fairmq/FairMQTransportFactory.h
@@ -24,7 +24,7 @@
 #include <cstddef> // size_t
 
 class FairMQChannel;
-namespace fair { namespace mq { class ProgOptions; } }
+namespace fair::mq { class ProgOptions; }
 
 class FairMQTransportFactory
 {
@@ -171,15 +171,12 @@ class FairMQTransportFactory
     }
 };
 
-namespace fair
-{
-namespace mq
+namespace fair::mq
 {
 
 using TransportFactory = FairMQTransportFactory;
 struct TransportFactoryError : std::runtime_error { using std::runtime_error::runtime_error; };
 
-} /* namespace mq */
-} /* namespace fair */
+} // namespace fair::mq
 
 #endif /* FAIRMQTRANSPORTFACTORY_H_ */
diff --git a/fairmq/FairMQUnmanagedRegion.h b/fairmq/FairMQUnmanagedRegion.h
index a353e0b6..46a3855c 100644
--- a/fairmq/FairMQUnmanagedRegion.h
+++ b/fairmq/FairMQUnmanagedRegion.h
@@ -104,9 +104,7 @@ inline std::ostream& operator<<(std::ostream& os, const FairMQRegionEvent& event
     }
 }
 
-namespace fair
-{
-namespace mq
+namespace fair::mq
 {
 
 using RegionCallback = FairMQRegionCallback;
@@ -118,7 +116,6 @@ using RegionBlock = FairMQRegionBlock;
 using UnmanagedRegion = FairMQUnmanagedRegion;
 using UnmanagedRegionPtr = FairMQUnmanagedRegionPtr;
 
-} /* namespace mq */
-} /* namespace fair */
+} // namespace fair::mq
 
 #endif /* FAIRMQUNMANAGEDREGION_H_ */
diff --git a/fairmq/JSONParser.cxx b/fairmq/JSONParser.cxx
index b2665af4..5c945d25 100644
--- a/fairmq/JSONParser.cxx
+++ b/fairmq/JSONParser.cxx
@@ -30,9 +30,7 @@ using namespace fair::mq;
 using namespace fair::mq::tools;
 using namespace boost::property_tree;
 
-namespace fair
-{
-namespace mq
+namespace fair::mq
 {
 
 fair::mq::Properties PtreeParser(const ptree& pt, const string& id)
@@ -185,5 +183,4 @@ void SubChannelParser(const ptree& channelTree, fair::mq::Properties& properties
 }
 
 } // helper namespace
-} // namespace mq
-} // namespace fair
+} // namespace fair::mq
diff --git a/fairmq/JSONParser.h b/fairmq/JSONParser.h
index d57cb802..f832683b 100644
--- a/fairmq/JSONParser.h
+++ b/fairmq/JSONParser.h
@@ -21,9 +21,7 @@
 #include <stdexcept>
 #include <string>
 
-namespace fair
-{
-namespace mq
+namespace fair::mq
 {
 
 struct ParserError : std::runtime_error { using std::runtime_error::runtime_error; };
@@ -41,7 +39,6 @@ void SubChannelParser(const boost::property_tree::ptree& tree, fair::mq::Propert
 
 } // helper namespace
 
-} // namespace mq
-} // namespace fair
+} // namespace fair::mq
 
 #endif /* FAIR_MQ_JSONPARSER_H */
diff --git a/fairmq/MemoryResourceTools.h b/fairmq/MemoryResourceTools.h
index 7ad7ebc9..45391680 100644
--- a/fairmq/MemoryResourceTools.h
+++ b/fairmq/MemoryResourceTools.h
@@ -15,8 +15,8 @@
 #include <fairmq/FairMQTransportFactory.h>
 #include <fairmq/MemoryResources.h>
 
-namespace fair {
-namespace mq {
+namespace fair::mq
+{
 
 using BytePmrAllocator = pmr::polymorphic_allocator<fair::mq::byte>;
 
@@ -62,5 +62,4 @@ FairMQMessagePtr getMessage(ContainerT &&container_, FairMQMemoryResource *targe
     return message;
 }
 
-} /* namespace mq */
-} /* namespace fair */
+} // namespace fair::mq
diff --git a/fairmq/MemoryResources.h b/fairmq/MemoryResources.h
index 396f66ef..fe02d346 100644
--- a/fairmq/MemoryResources.h
+++ b/fairmq/MemoryResources.h
@@ -26,8 +26,8 @@ class FairMQTransportFactory;
 #include <stdexcept>
 #include <utility>
 
-namespace fair {
-namespace mq {
+namespace fair::mq
+{
 
 using byte = unsigned char;
 namespace pmr = boost::container::pmr;
@@ -107,7 +107,6 @@ class ChannelResource : public FairMQMemoryResource
     };
 };
 
-} /* namespace mq */
-} /* namespace fair */
+} // namespace fair::mq
 
 #endif /* FAIR_MQ_MEMORY_RESOURCES_H */
diff --git a/fairmq/Plugin.h b/fairmq/Plugin.h
index 870d5420..e7fee637 100644
--- a/fairmq/Plugin.h
+++ b/fairmq/Plugin.h
@@ -24,9 +24,7 @@
 #include <tuple>
 #include <utility>
 
-namespace fair
-{
-namespace mq
+namespace fair::mq
 {
 
 /**
@@ -133,8 +131,7 @@ class Plugin
     PluginServices* fPluginServices;
 }; /* class Plugin */
 
-} /* namespace mq */
-} /* namespace fair */
+} // namespace fair::mq
 
 #define REGISTER_FAIRMQ_PLUGIN(KLASS, NAME, VERSION, MAINTAINER, HOMEPAGE, PROGOPTIONS) \
 static auto Make_##NAME##_Plugin(fair::mq::PluginServices* pluginServices) -> std::unique_ptr<fair::mq::Plugin> \
diff --git a/fairmq/PluginManager.h b/fairmq/PluginManager.h
index eb5866ab..848c3fd2 100644
--- a/fairmq/PluginManager.h
+++ b/fairmq/PluginManager.h
@@ -30,9 +30,7 @@
 #include <vector>
 #include <utility> // forward
 
-namespace fair
-{
-namespace mq
+namespace fair::mq
 {
 
 /**
@@ -125,7 +123,6 @@ class PluginManager
     std::map<std::string, boost::program_options::options_description> fPluginProgOptions;
 }; /* class PluginManager */
 
-} /* namespace mq */
-} /* namespace fair */
+} // namespace fair::mq
 
 #endif /* FAIR_MQ_PLUGINMANAGER_H */
diff --git a/fairmq/PluginServices.h b/fairmq/PluginServices.h
index 9bb6814e..6bb933fa 100644
--- a/fairmq/PluginServices.h
+++ b/fairmq/PluginServices.h
@@ -26,9 +26,7 @@
 #include <unordered_map>
 #include <vector>
 
-namespace fair
-{
-namespace mq
+namespace fair::mq
 {
 
 /**
@@ -281,7 +279,6 @@ class PluginServices
     std::condition_variable fReleaseDeviceControlCondition;
 }; /* class PluginServices */
 
-} /* namespace mq */
-} /* namespace fair */
+} // namespace fair::mq
 
 #endif /* FAIR_MQ_PLUGINSERVICES_H */
diff --git a/fairmq/ProgOptions.cxx b/fairmq/ProgOptions.cxx
index 6565fea5..9f805dec 100644
--- a/fairmq/ProgOptions.cxx
+++ b/fairmq/ProgOptions.cxx
@@ -39,9 +39,7 @@ struct ValInfo
     string origin;
 };
 
-namespace fair
-{
-namespace mq
+namespace fair::mq
 {
 
 ValInfo ConvertVarValToValInfo(const po::variable_value& v)
@@ -449,6 +447,4 @@ void ProgOptions::PrintOptionsRaw() const
     }
 }
 
-
-} // namespace mq
-} // namespace fair
+} // namespace fair::mq
diff --git a/fairmq/ProgOptions.h b/fairmq/ProgOptions.h
index 7cbba282..4d679763 100644
--- a/fairmq/ProgOptions.h
+++ b/fairmq/ProgOptions.h
@@ -26,9 +26,7 @@
 #include <vector>
 #include <stdexcept>
 
-namespace fair
-{
-namespace mq
+namespace fair::mq
 {
 
 struct PropertyNotFoundError : std::runtime_error { using std::runtime_error::runtime_error; };
@@ -270,7 +268,6 @@ class ProgOptions
     mutable std::mutex fMtx;
 };
 
-} // namespace mq
-} // namespace fair
+} // namespace fair::mq
 
 #endif /* FAIR_MQ_PROGOPTIONS_H */
diff --git a/fairmq/ProgOptionsFwd.h b/fairmq/ProgOptionsFwd.h
index daea799a..9a805ae0 100644
--- a/fairmq/ProgOptionsFwd.h
+++ b/fairmq/ProgOptionsFwd.h
@@ -9,13 +9,10 @@
 #ifndef FAIR_MQ_PROGOPTIONSFWD_H
 #define FAIR_MQ_PROGOPTIONSFWD_H
 
-namespace fair
-{
-namespace mq
+namespace fair::mq
 {
 class ProgOptions;
 }
-}
 
 using FairMQProgOptions = fair::mq::ProgOptions;
 
diff --git a/fairmq/Properties.cxx b/fairmq/Properties.cxx
index 19b51a76..fd710fd4 100644
--- a/fairmq/Properties.cxx
+++ b/fairmq/Properties.cxx
@@ -13,9 +13,7 @@
 using namespace std;
 using boost::any_cast;
 
-namespace fair
-{
-namespace mq
+namespace fair::mq
 {
 
 template<class T>
@@ -143,5 +141,4 @@ unordered_map<type_index, void(*)(const EventManager&, const string&, const Prop
     { type_index(typeid(vector<boost::filesystem::path>)), [](const EventManager& em, const string& k, const Property& p) { em.Emit<PropertyChange, vector<boost::filesystem::path>>(k, any_cast<vector<boost::filesystem::path>>(p)); } },
 };
 
-} // namespace mq
-} // namespace fair
+} // namespace fair::mq
diff --git a/fairmq/Properties.h b/fairmq/Properties.h
index fe6442bb..b2b6b802 100644
--- a/fairmq/Properties.h
+++ b/fairmq/Properties.h
@@ -22,9 +22,7 @@
 #include <typeinfo>
 #include <utility> // pair
 
-namespace fair
-{
-namespace mq
+namespace fair::mq
 {
 
 using Property = boost::any;
@@ -72,7 +70,6 @@ class PropertyHelper
     static std::unordered_map<std::type_index, std::function<std::pair<std::string, std::string>(const Property&)>> fTypeInfos;
 };
 
-}
 }
 
 #endif /* FAIR_MQ_PROPERTIES_H */
diff --git a/fairmq/StateMachine.cxx b/fairmq/StateMachine.cxx
index cb118f1d..c5b21893 100644
--- a/fairmq/StateMachine.cxx
+++ b/fairmq/StateMachine.cxx
@@ -35,9 +35,7 @@ using namespace boost::msm::front;
 using namespace boost::msm::back;
 namespace bmpl = boost::mpl;
 
-namespace fair
-{
-namespace mq
+namespace fair::mq
 {
 namespace fsm
 {
@@ -239,8 +237,7 @@ struct Machine_ : public state_machine_def<Machine_>
 using FairMQFSM = state_machine<Machine_>;
 
 } // namespace fsm
-} // namespace mq
-} // namespace fair
+} // namespace fair::mq
 
 using namespace fair::mq::fsm;
 using namespace fair::mq;
diff --git a/fairmq/StateMachine.h b/fairmq/StateMachine.h
index bac4f41f..1f1386cf 100644
--- a/fairmq/StateMachine.h
+++ b/fairmq/StateMachine.h
@@ -16,9 +16,7 @@
 #include <functional>
 #include <stdexcept>
 
-namespace fair
-{
-namespace mq
+namespace fair::mq
 {
 
 class StateMachine
@@ -56,7 +54,6 @@ class StateMachine
     std::shared_ptr<void> fFsm;
 };
 
-} // namespace mq
-} // namespace fair
+} // namespace fair::mq
 
 #endif /* FAIRMQSTATEMACHINE_H_ */
diff --git a/fairmq/StateQueue.h b/fairmq/StateQueue.h
index b65dc295..61db5a54 100644
--- a/fairmq/StateQueue.h
+++ b/fairmq/StateQueue.h
@@ -17,9 +17,7 @@
 #include <utility> // pair
 #include <condition_variable>
 
-namespace fair
-{
-namespace mq
+namespace fair::mq
 {
 
 class StateQueue
@@ -88,7 +86,6 @@ class StateQueue
     std::condition_variable fCV;
 };
 
-} // namespace mq
-} // namespace fair
+} // namespace fair::mq
 
-#endif /* FAIRMQSTATEQUEUE_H_ */
\ No newline at end of file
+#endif /* FAIRMQSTATEQUEUE_H_ */
diff --git a/fairmq/States.cxx b/fairmq/States.cxx
index 2b8261ef..1f733c46 100644
--- a/fairmq/States.cxx
+++ b/fairmq/States.cxx
@@ -13,9 +13,7 @@
 
 using namespace std;
 
-namespace fair
-{
-namespace mq
+namespace fair::mq
 {
 
 array<string, 16> stateNames =
@@ -114,5 +112,4 @@ Transition GetTransition(const string& transition)
     return transitions.at(transition);
 }
 
-} // namespace mq
-} // namespace fair
+} // namespace fair::mq
diff --git a/fairmq/States.h b/fairmq/States.h
index 2d540ed6..14090c45 100644
--- a/fairmq/States.h
+++ b/fairmq/States.h
@@ -13,9 +13,7 @@
 #include <ostream>
 #include <stdexcept>
 
-namespace fair
-{
-namespace mq
+namespace fair::mq
 {
 
 enum class State : int
@@ -64,7 +62,6 @@ struct DeviceErrorState : std::runtime_error { using std::runtime_error::runtime
 inline std::ostream& operator<<(std::ostream& os, const State& state) { return os << GetStateName(state); }
 inline std::ostream& operator<<(std::ostream& os, const Transition& transition) { return os << GetTransitionName(transition); }
 
-} // namespace mq
-} // namespace fair
+} // namespace fair::mq
 
 #endif /* FAIRMQSTATES_H_ */
diff --git a/fairmq/SuboptParser.cxx b/fairmq/SuboptParser.cxx
index 397906f0..2e53fe18 100644
--- a/fairmq/SuboptParser.cxx
+++ b/fairmq/SuboptParser.cxx
@@ -23,9 +23,7 @@
 using boost::property_tree::ptree;
 using namespace std;
 
-namespace fair
-{
-namespace mq
+namespace fair::mq
 {
 
 enum channelOptionKeyIds
@@ -120,4 +118,3 @@ Properties SuboptParser(const vector<string>& channelConfig, const string& devic
 }
 
 }
-}
diff --git a/fairmq/SuboptParser.h b/fairmq/SuboptParser.h
index 1ed99300..e8c50b56 100644
--- a/fairmq/SuboptParser.h
+++ b/fairmq/SuboptParser.h
@@ -19,9 +19,7 @@
 #include <vector>
 #include <string>
 
-namespace fair
-{
-namespace mq
+namespace fair::mq
 {
 
 /**
@@ -43,7 +41,6 @@ namespace mq
 
 Properties SuboptParser(const std::vector<std::string>& channelConfig, const std::string& deviceId);
 
-}
 }
 
 #endif /* FAIR_MQ_SUBOPTPARSER_H */
diff --git a/fairmq/Transports.h b/fairmq/Transports.h
index c4b3d155..fd37ac0f 100644
--- a/fairmq/Transports.h
+++ b/fairmq/Transports.h
@@ -17,9 +17,7 @@
 #include <string>
 #include <unordered_map>
 
-namespace fair
-{
-namespace mq
+namespace fair::mq
 {
 
 enum class Transport
@@ -32,8 +30,7 @@ enum class Transport
 
 struct TransportError : std::runtime_error { using std::runtime_error::runtime_error; };
 
-} /* namespace mq */
-} /* namespace fair */
+} // namespace fair::mq
 
 namespace std
 {
@@ -43,9 +40,7 @@ struct hash<fair::mq::Transport> : fair::mq::tools::HashEnum<fair::mq::Transport
 
 } /* namespace std */
 
-namespace fair
-{
-namespace mq
+namespace fair::mq
 {
 
 static std::unordered_map<std::string, Transport> TransportTypes {
@@ -74,7 +69,6 @@ try {
     throw TransportError(tools::ToString("Unknown transport provided: ", transport));
 }
 
-} /* namespace mq */
-} /* namespace fair */
+} // namespace fair::mq
 
 #endif /* FAIR_MQ_TRANSPORTS_H */
diff --git a/fairmq/ofi/Context.cxx b/fairmq/ofi/Context.cxx
index f3b06e72..aafec40d 100644
--- a/fairmq/ofi/Context.cxx
+++ b/fairmq/ofi/Context.cxx
@@ -22,11 +22,7 @@
 #include <string.h>
 #include <sys/socket.h>
 
-namespace fair
-{
-namespace mq
-{
-namespace ofi
+namespace fair::mq::ofi
 {
 
 using namespace std;
@@ -134,6 +130,4 @@ auto Context::MakeSendMessage(size_t size) -> MessagePtr
     return fSendFactory.CreateMessage(size);
 }
 
-} /* namespace ofi */
-} /* namespace mq */
-} /* namespace fair */
+} // namespace fair::mq::ofi
diff --git a/fairmq/ofi/Context.h b/fairmq/ofi/Context.h
index 814461e9..b6a821d9 100644
--- a/fairmq/ofi/Context.h
+++ b/fairmq/ofi/Context.h
@@ -24,11 +24,7 @@
 #include <thread>
 #include <vector>
 
-namespace fair
-{
-namespace mq
-{
-namespace ofi
+namespace fair::mq::ofi
 {
 
 enum class ConnectionType : bool { Bind, Connect };
@@ -88,8 +84,6 @@ class Context
 
 struct ContextError : std::runtime_error { using std::runtime_error::runtime_error; };
 
-} /* namespace ofi */
-} /* namespace mq */
-} /* namespace fair */
+} // namespace fair::mq::ofi
 
 #endif /* FAIR_MQ_OFI_CONTEXT_H */
diff --git a/fairmq/ofi/ControlMessages.h b/fairmq/ofi/ControlMessages.h
index 2f78798a..f8082fe3 100644
--- a/fairmq/ofi/ControlMessages.h
+++ b/fairmq/ofi/ControlMessages.h
@@ -17,8 +17,8 @@
 #include <memory>
 #include <type_traits>
 
-namespace boost {
-namespace asio {
+namespace boost::asio
+{
 
 template<typename PodType>
 auto buffer(const PodType& obj) -> boost::asio::const_buffer
@@ -26,12 +26,10 @@ auto buffer(const PodType& obj) -> boost::asio::const_buffer
     return boost::asio::const_buffer(static_cast<const void*>(&obj), sizeof(PodType));
 }
 
-}   // namespace asio
-}   // namespace boost
+} // namespace boost::asio
 
-namespace fair {
-namespace mq {
-namespace ofi {
+namespace fair::mq::ofi
+{
 
 enum class ControlMessageType
 {
@@ -109,8 +107,6 @@ auto MakeControlMessage(Args&&... args) -> ControlMessage
     return ctrl;
 }
 
-}   // namespace ofi
-}   // namespace mq
-}   // namespace fair
+} // namespace fair::mq::ofi
 
 #endif /* FAIR_MQ_OFI_CONTROLMESSAGES_H */ 
diff --git a/fairmq/ofi/Message.cxx b/fairmq/ofi/Message.cxx
index 1cf56c6c..9ff9df5b 100644
--- a/fairmq/ofi/Message.cxx
+++ b/fairmq/ofi/Message.cxx
@@ -14,11 +14,7 @@
 #include <cstdlib>
 #include <zmq.h>
 
-namespace fair
-{
-namespace mq
-{
-namespace ofi
+namespace fair::mq::ofi
 {
 
 using namespace std;
@@ -201,6 +197,4 @@ Message::~Message()
     }
 }
 
-} /* namespace ofi */
-} /* namespace mq */
-} /* namespace fair */
+} // namespace fair::mq::ofi
diff --git a/fairmq/ofi/Message.h b/fairmq/ofi/Message.h
index e1c1daab..db18f6f0 100644
--- a/fairmq/ofi/Message.h
+++ b/fairmq/ofi/Message.h
@@ -17,11 +17,7 @@
 #include <cstddef> // size_t
 #include <zmq.h>
 
-namespace fair
-{
-namespace mq
-{
-namespace ofi
+namespace fair::mq::ofi
 {
 
 /**
@@ -77,8 +73,6 @@ class Message final : public fair::mq::Message
     boost::container::pmr::memory_resource* fPmr;
 }; /* class Message */  
 
-} /* namespace ofi */
-} /* namespace mq */
-} /* namespace fair */
+} // namespace fair::mq::ofi
 
 #endif /* FAIR_MQ_OFI_MESSAGE_H */
diff --git a/fairmq/ofi/Poller.cxx b/fairmq/ofi/Poller.cxx
index bed8b9e9..0dad03a1 100644
--- a/fairmq/ofi/Poller.cxx
+++ b/fairmq/ofi/Poller.cxx
@@ -13,11 +13,7 @@
 
 #include <zmq.h>
 
-namespace fair
-{
-namespace mq
-{
-namespace ofi
+namespace fair::mq::ofi
 {
 
 using namespace std;
@@ -153,6 +149,4 @@ Poller::~Poller()
     delete[] fItems;
 }
 
-} /* namespace ofi */
-} /* namespace mq */
-} /* namespace fair */
+} // namespace fair::mq::ofi
diff --git a/fairmq/ofi/Poller.h b/fairmq/ofi/Poller.h
index a6d08a2d..cb264f18 100644
--- a/fairmq/ofi/Poller.h
+++ b/fairmq/ofi/Poller.h
@@ -18,11 +18,7 @@
 
 #include <zmq.h>
 
-namespace fair
-{
-namespace mq
-{
-namespace ofi
+namespace fair::mq::ofi
 {
 
 class TransportFactory;
@@ -63,8 +59,6 @@ class Poller final : public FairMQPoller
     std::unordered_map<std::string, int> fOffsetMap;
 }; /* class Poller */
 
-} /* namespace ofi */
-} /* namespace mq */
-} /* namespace fair */
+} // namespace fair::mq::ofi
 
 #endif /* FAIR_MQ_OFI_POLLER_H */
diff --git a/fairmq/ofi/Socket.cxx b/fairmq/ofi/Socket.cxx
index 0a99e5c2..809f69b3 100644
--- a/fairmq/ofi/Socket.cxx
+++ b/fairmq/ofi/Socket.cxx
@@ -25,11 +25,7 @@
 #include <mutex>
 #include <queue>
 
-namespace fair
-{
-namespace mq
-{
-namespace ofi
+namespace fair::mq::ofi
 {
 
 using namespace std;
@@ -683,6 +679,4 @@ Socket::~Socket()
     }
 }
 
-} /* namespace ofi */
-} /* namespace mq */
-} /* namespace fair */
+} // namespace fair::mq::ofi
diff --git a/fairmq/ofi/Socket.h b/fairmq/ofi/Socket.h
index 8f52e2c8..ebd7fe9f 100644
--- a/fairmq/ofi/Socket.h
+++ b/fairmq/ofi/Socket.h
@@ -23,11 +23,7 @@
 #include <mutex>
 
 
-namespace fair
-{
-namespace mq
-{
-namespace ofi
+namespace fair::mq::ofi
 {
 
 /**
@@ -120,8 +116,6 @@ class Socket final : public fair::mq::Socket
 
 struct SilentSocketError : SocketError { using SocketError::SocketError; };
 
-} /* namespace ofi */
-} /* namespace mq */
-} /* namespace fair */
+} // namespace fair::mq::ofi
 
 #endif /* FAIR_MQ_OFI_SOCKET_H */
diff --git a/fairmq/ofi/TransportFactory.cxx b/fairmq/ofi/TransportFactory.cxx
index 51ac1ff3..297f4a4a 100644
--- a/fairmq/ofi/TransportFactory.cxx
+++ b/fairmq/ofi/TransportFactory.cxx
@@ -13,11 +13,7 @@
 
 #include <stdexcept>
 
-namespace fair
-{
-namespace mq
-{
-namespace ofi
+namespace fair::mq::ofi
 {
 
 using namespace std;
@@ -121,6 +117,4 @@ auto TransportFactory::GetType() const -> Transport
     return Transport::OFI;
 }
 
-} /* namespace ofi */
-} /* namespace mq */
-} /* namespace fair */
+} // namespace fair::mq::ofi
diff --git a/fairmq/ofi/TransportFactory.h b/fairmq/ofi/TransportFactory.h
index b0d55930..d3dda3ce 100644
--- a/fairmq/ofi/TransportFactory.h
+++ b/fairmq/ofi/TransportFactory.h
@@ -15,11 +15,7 @@
 
 #include <asiofi.hpp>
 
-namespace fair
-{
-namespace mq
-{
-namespace ofi
+namespace fair::mq::ofi
 {
 
 /**
@@ -69,8 +65,6 @@ class TransportFactory final : public FairMQTransportFactory
     asiofi::allocated_pool_resource fMemoryResource;
 }; /* class TransportFactory */  
 
-} /* namespace ofi */
-} /* namespace mq */
-} /* namespace fair */
+} // namespace fair::mq::ofi
 
 #endif /* FAIR_MQ_OFI_TRANSPORTFACTORY_H */
diff --git a/fairmq/plugins/Control.cxx b/fairmq/plugins/Control.cxx
index a975ce7b..9dedf3fa 100644
--- a/fairmq/plugins/Control.cxx
+++ b/fairmq/plugins/Control.cxx
@@ -43,11 +43,7 @@ namespace
     }
 }
 
-namespace fair
-{
-namespace mq
-{
-namespace plugins
+namespace fair::mq::plugins
 {
 
 Control::Control(const string& name, const Plugin::Version version, const string& maintainer, const string& homepage, PluginServices* pluginServices)
@@ -475,6 +471,4 @@ Control::~Control()
     UnsubscribeFromDeviceStateChange();
 }
 
-} /* namespace plugins */
-} /* namespace mq */
-} /* namespace fair */
+} // namespace fair::mq::plugins
diff --git a/fairmq/plugins/Control.h b/fairmq/plugins/Control.h
index 9d0695dc..c3976185 100644
--- a/fairmq/plugins/Control.h
+++ b/fairmq/plugins/Control.h
@@ -21,11 +21,7 @@
 #include <atomic>
 #include <stdexcept>
 
-namespace fair
-{
-namespace mq
-{
-namespace plugins
+namespace fair::mq::plugins
 {
 
 class Control : public Plugin
@@ -68,8 +64,6 @@ REGISTER_FAIRMQ_PLUGIN(
                                   // boost::optional<boost::program_options::options_description>
 )
 
-} /* namespace plugins */
-} /* namespace mq */
-} /* namespace fair */
+} // namespace fair::mq::plugins
 
 #endif /* FAIR_MQ_PLUGINS_CONTROL */
diff --git a/fairmq/plugins/DDS/DDS.cxx b/fairmq/plugins/DDS/DDS.cxx
index 9d396552..e758e617 100644
--- a/fairmq/plugins/DDS/DDS.cxx
+++ b/fairmq/plugins/DDS/DDS.cxx
@@ -22,11 +22,7 @@
 using namespace std;
 using fair::mq::tools::ToString;
 
-namespace fair
-{
-namespace mq
-{
-namespace plugins
+namespace fair::mq::plugins
 {
 
 DDS::DDS(const string& name,
@@ -458,6 +454,4 @@ DDS::~DDS()
     }
 }
 
-} /* namespace plugins */
-} /* namespace mq */
-} /* namespace fair */
+} // namespace fair::mq::plugins
diff --git a/fairmq/plugins/DDS/DDS.h b/fairmq/plugins/DDS/DDS.h
index 10f6e6d4..4c82a8b4 100644
--- a/fairmq/plugins/DDS/DDS.h
+++ b/fairmq/plugins/DDS/DDS.h
@@ -32,11 +32,7 @@
 #include <utility> // pair
 #include <vector>
 
-namespace fair
-{
-namespace mq
-{
-namespace plugins
+namespace fair::mq::plugins
 {
 
 struct DDSConfig
@@ -196,8 +192,6 @@ REGISTER_FAIRMQ_PLUGIN(
     DDSProgramOptions                            // custom program options for the plugin
 )
 
-} /* namespace plugins */
-} /* namespace mq */
-} /* namespace fair */
+} // namespace fair::mq::plugins
 
 #endif /* FAIR_MQ_PLUGINS_DDS */
diff --git a/fairmq/plugins/PMIx/PMIxPlugin.cxx b/fairmq/plugins/PMIx/PMIxPlugin.cxx
index 00aeb97d..bc2a81ff 100644
--- a/fairmq/plugins/PMIx/PMIxPlugin.cxx
+++ b/fairmq/plugins/PMIx/PMIxPlugin.cxx
@@ -18,11 +18,7 @@
 using namespace std;
 using namespace fair::mq::sdk::cmd;
 
-namespace fair
-{
-namespace mq
-{
-namespace plugins
+namespace fair::mq::plugins
 {
 
 PMIxPlugin::PMIxPlugin(const string& name,
@@ -304,6 +300,4 @@ auto PMIxPlugin::WaitForExitingAck() -> void
     });
 }
 
-} /* namespace plugins */
-} /* namespace mq */
-} /* namespace fair */
+} // namespace fair::mq::plugins
diff --git a/fairmq/plugins/PMIx/PMIxPlugin.h b/fairmq/plugins/PMIx/PMIxPlugin.h
index e22db4ef..ca3e305b 100644
--- a/fairmq/plugins/PMIx/PMIxPlugin.h
+++ b/fairmq/plugins/PMIx/PMIxPlugin.h
@@ -24,11 +24,7 @@
 #include <unistd.h>
 #include <vector>
 
-namespace fair
-{
-namespace mq
-{
-namespace plugins
+namespace fair::mq::plugins
 {
 
 class PMIxPlugin : public Plugin
@@ -88,8 +84,6 @@ REGISTER_FAIRMQ_PLUGIN(
     PMIxProgramOptions                           // custom program options for the plugin
 )
 
-} /* namespace plugins */
-} /* namespace mq */
-} /* namespace fair */
+} // namespace fair::mq::plugins
 
 #endif /* FAIR_MQ_PLUGINS_PMIX */
diff --git a/fairmq/plugins/config/Config.cxx b/fairmq/plugins/config/Config.cxx
index 22a53632..987b5752 100644
--- a/fairmq/plugins/config/Config.cxx
+++ b/fairmq/plugins/config/Config.cxx
@@ -15,11 +15,7 @@
 
 using namespace std;
 
-namespace fair
-{
-namespace mq
-{
-namespace plugins
+namespace fair::mq::plugins
 {
 
 Config::Config(const string& name, const Plugin::Version version, const string& maintainer, const string& homepage, PluginServices* pluginServices)
@@ -89,6 +85,4 @@ Config::~Config()
     UnsubscribeFromDeviceStateChange();
 }
 
-} /* namespace plugins */
-} /* namespace mq */
-} /* namespace fair */
+} // namespace fair::mq::plugins
diff --git a/fairmq/plugins/config/Config.h b/fairmq/plugins/config/Config.h
index db1a03a0..28515f1f 100644
--- a/fairmq/plugins/config/Config.h
+++ b/fairmq/plugins/config/Config.h
@@ -14,11 +14,7 @@
 
 #include <string>
 
-namespace fair
-{
-namespace mq
-{
-namespace plugins
+namespace fair::mq::plugins
 {
 
 class Config : public Plugin
@@ -40,8 +36,6 @@ REGISTER_FAIRMQ_PLUGIN(
     ConfigPluginProgramOptions
 )
 
-} /* namespace plugins */
-} /* namespace mq */
-} /* namespace fair */
+} // namespace fair::mq::plugins
 
 #endif /* FAIR_MQ_PLUGINS_CONFIG */
diff --git a/fairmq/sdk/AsioAsyncOp.h b/fairmq/sdk/AsioAsyncOp.h
index d5b60507..a1a76a27 100644
--- a/fairmq/sdk/AsioAsyncOp.h
+++ b/fairmq/sdk/AsioAsyncOp.h
@@ -29,9 +29,8 @@
 #define FAIR_LOG LOG
 #endif /* ifndef FAIR_LOG */
 
-namespace fair {
-namespace mq {
-namespace sdk {
+namespace fair::mq::sdk
+{
 
 template<typename... SignatureArgTypes>
 struct AsioAsyncOpImplBase
@@ -219,9 +218,6 @@ struct AsioAsyncOp<Executor,
     }
 };
 
-} /* namespace sdk */
-} /* namespace mq */
-} /* namespace fair */
+} // namespace fair::mq::sdk
 
 #endif /* FAIR_MQ_SDK_ASIOASYNCOP_H */
-
diff --git a/fairmq/sdk/AsioBase.h b/fairmq/sdk/AsioBase.h
index eee5e5ab..6170e263 100644
--- a/fairmq/sdk/AsioBase.h
+++ b/fairmq/sdk/AsioBase.h
@@ -14,9 +14,8 @@
 #include <memory>
 #include <utility>
 
-namespace fair {
-namespace mq {
-namespace sdk {
+namespace fair::mq::sdk
+{
 
 using DefaultExecutor = asio::any_io_executor;
 using DefaultAllocator = std::allocator<int>;
@@ -69,8 +68,6 @@ class AsioBase
     AllocatorType fAllocator;
 };
 
-} /* namespace sdk */
-} /* namespace mq */
-} /* namespace fair */
+} // namespace fair::mq::sdk
 
 #endif /* FAIR_MQ_SDK_ASIOBASE_H */
diff --git a/fairmq/sdk/DDSAgent.h b/fairmq/sdk/DDSAgent.h
index 153d74ad..a3db515c 100644
--- a/fairmq/sdk/DDSAgent.h
+++ b/fairmq/sdk/DDSAgent.h
@@ -16,9 +16,8 @@
 #include <chrono>
 #include <cstdint>
 
-namespace fair {
-namespace mq {
-namespace sdk {
+namespace fair::mq::sdk
+{
 
 /**
  * @class DDSAgent <fairmq/sdk/DDSAgent.h>
@@ -74,8 +73,6 @@ class DDSAgent
     std::string fUsername;
 };
 
-}   // namespace sdk
-}   // namespace mq
-}   // namespace fair
+} // namespace fair::mq::sdk
 
 #endif /* FAIR_MQ_SDK_DDSSAGENT_H */
diff --git a/fairmq/sdk/DDSCollection.h b/fairmq/sdk/DDSCollection.h
index a17a7d94..2a56700c 100644
--- a/fairmq/sdk/DDSCollection.h
+++ b/fairmq/sdk/DDSCollection.h
@@ -14,9 +14,8 @@
 #include <ostream>
 #include <cstdint>
 
-namespace fair {
-namespace mq {
-namespace sdk {
+namespace fair::mq::sdk
+{
 
 /**
  * @class DDSCollection <fairmq/sdk/DDSCollection.h>
@@ -42,8 +41,6 @@ class DDSCollection
     Id fId;
 };
 
-}   // namespace sdk
-}   // namespace mq
-}   // namespace fair
+} // namespace fair::mq::sdk
 
 #endif /* FAIR_MQ_SDK_DDSCOLLECTION_H */
diff --git a/fairmq/sdk/DDSEnvironment.cxx b/fairmq/sdk/DDSEnvironment.cxx
index 7a66abab..9eaf64d0 100644
--- a/fairmq/sdk/DDSEnvironment.cxx
+++ b/fairmq/sdk/DDSEnvironment.cxx
@@ -16,9 +16,8 @@
 #include <sstream>
 #include <utility>
 
-namespace fair {
-namespace mq {
-namespace sdk {
+namespace fair::mq::sdk
+{
 
 struct DDSEnvironment::Impl
 {
@@ -133,6 +132,4 @@ auto operator<<(std::ostream& os, DDSEnvironment env) -> std::ostream&
               << "$DDS_CONFIG_HOME: " << env.GetConfigHome() / DDSEnvironment::Path(".DDS");
 }
 
-}   // namespace sdk
-}   // namespace mq
-}   // namespace fair
+} // namespace fair::mq::sdk
diff --git a/fairmq/sdk/DDSEnvironment.h b/fairmq/sdk/DDSEnvironment.h
index 2ba72eca..529f1ba1 100644
--- a/fairmq/sdk/DDSEnvironment.h
+++ b/fairmq/sdk/DDSEnvironment.h
@@ -13,9 +13,8 @@
 #include <memory>
 #include <ostream>
 
-namespace fair {
-namespace mq {
-namespace sdk {
+namespace fair::mq::sdk
+{
 
 /**
  * @class DDSEnvironment DDSSession.h <fairmq/sdk/DDSSession.h>
@@ -40,8 +39,6 @@ class DDSEnvironment
 
 using DDSEnv = DDSEnvironment;
 
-}   // namespace sdk
-}   // namespace mq
-}   // namespace fair
+} // namespace fair::mq::sdk
 
 #endif /* FAIR_MQ_SDK_DDSENVIRONMENT_H */
diff --git a/fairmq/sdk/DDSInfo.h.in b/fairmq/sdk/DDSInfo.h.in
index 156d219c..e3c9d723 100644
--- a/fairmq/sdk/DDSInfo.h.in
+++ b/fairmq/sdk/DDSInfo.h.in
@@ -11,23 +11,11 @@
 
 #include <string>
 
-namespace dds {
-namespace tools_api {
+namespace dds::tools_api { class CSession; }
+namespace dds::topology_api { class CTopology; }
 
-class CSession;
-
-}   // namespace tools_api
-
-namespace topology_api {
-
-class CTopology;
-
-}   // namespace topology_api
-}   // namespace dds
-
-namespace fair {
-namespace mq {
-namespace sdk {
+namespace fair::mq::sdk
+{
 
 const std::string DDSVersion("@DDS_VERSION@");
 const std::string DDSInstallPrefix("@DDS_INSTALL_PREFIX@");
@@ -36,8 +24,6 @@ const std::string DDSIncludeDir("@DDS_INCDIR@");
 const std::string DDSLibraryDir("@DDS_LIBDIR@");
 const std::string DDSPluginDir("@DDS_PLUGINDIR@");
 
-}   // namespace sdk
-}   // namespace mq
-}   // namespace fair
+} // namespace fair::mq::sdk
 
 #endif /* FAIR_MQ_SDK_DDSINFO_H */
diff --git a/fairmq/sdk/DDSSession.cxx b/fairmq/sdk/DDSSession.cxx
index dcc530af..f8e8dc53 100644
--- a/fairmq/sdk/DDSSession.cxx
+++ b/fairmq/sdk/DDSSession.cxx
@@ -25,9 +25,8 @@
 #include <utility>
 #include <vector>
 
-namespace fair {
-namespace mq {
-namespace sdk {
+namespace fair::mq::sdk
+{
 
 auto operator<<(std::ostream& os, DDSRMSPlugin plugin) -> std::ostream&
 {
@@ -384,6 +383,4 @@ auto getMostRecentRunningDDSSession(DDSEnv env) -> DDSSession
     return DDSSession(DDSSession::Id(sessionId), std::move(env));
 }
 
-}   // namespace sdk
-}   // namespace mq
-}   // namespace fair
+} // namespace fair::mq::sdk
diff --git a/fairmq/sdk/DDSSession.h b/fairmq/sdk/DDSSession.h
index d1ee9486..93034b9e 100644
--- a/fairmq/sdk/DDSSession.h
+++ b/fairmq/sdk/DDSSession.h
@@ -24,9 +24,8 @@
 #include <functional>
 #include <vector>
 
-namespace fair {
-namespace mq {
-namespace sdk {
+namespace fair::mq::sdk
+{
 
 /**
  * @enum DDSRMSPlugin DDSSession.h <fairmq/sdk/DDSSession.h>
@@ -114,8 +113,6 @@ class DDSSession
 
 auto getMostRecentRunningDDSSession(DDSEnv env = {}) -> DDSSession;
 
-}   // namespace sdk
-}   // namespace mq
-}   // namespace fair
+} // namespace fair::mq::sdk
 
 #endif /* FAIR_MQ_SDK_DDSSESSION_H */
diff --git a/fairmq/sdk/DDSTask.h b/fairmq/sdk/DDSTask.h
index d593b212..5be55853 100644
--- a/fairmq/sdk/DDSTask.h
+++ b/fairmq/sdk/DDSTask.h
@@ -14,9 +14,8 @@
 #include <ostream>
 #include <cstdint>
 
-namespace fair {
-namespace mq {
-namespace sdk {
+namespace fair::mq::sdk
+{
 
 /**
  * @class DDSTask <fairmq/sdk/DDSTask.h>
@@ -45,8 +44,6 @@ class DDSTask
     DDSCollection::Id fCollectionId;
 };
 
-}   // namespace sdk
-}   // namespace mq
-}   // namespace fair
+} // namespace fair::mq::sdk
 
 #endif /* FAIR_MQ_SDK_DDSTASK_H */
diff --git a/fairmq/sdk/DDSTopology.cxx b/fairmq/sdk/DDSTopology.cxx
index 51774011..09adfd9f 100644
--- a/fairmq/sdk/DDSTopology.cxx
+++ b/fairmq/sdk/DDSTopology.cxx
@@ -17,9 +17,8 @@
 #include <stdexcept>
 #include <utility>
 
-namespace fair {
-namespace mq {
-namespace sdk {
+namespace fair::mq::sdk
+{
 
 struct DDSTopology::Impl
 {
@@ -112,6 +111,4 @@ try {
     return os << "DDS topology: " << t.GetName();
 }
 
-}   // namespace sdk
-}   // namespace mq
-}   // namespace fair
+} // namespace fair::mq::sdk
diff --git a/fairmq/sdk/DDSTopology.h b/fairmq/sdk/DDSTopology.h
index b85ad7d7..e4166d22 100644
--- a/fairmq/sdk/DDSTopology.h
+++ b/fairmq/sdk/DDSTopology.h
@@ -18,9 +18,8 @@
 #include <string>
 #include <vector>
 
-namespace fair {
-namespace mq {
-namespace sdk {
+namespace fair::mq::sdk
+{
 
 /**
  * @class DDSTopology DDSTopology.h <fairmq/sdk/DDSTopology.h>
@@ -71,8 +70,6 @@ class DDSTopology
 
 using DDSTopo = DDSTopology;
 
-}   // namespace sdk
-}   // namespace mq
-}   // namespace fair
+} // namespace fair::mq::sdk
 
 #endif /* FAIR_MQ_SDK_DDSTOPOLOGY_H */
diff --git a/fairmq/sdk/Error.cxx b/fairmq/sdk/Error.cxx
index fd61959c..865994d1 100644
--- a/fairmq/sdk/Error.cxx
+++ b/fairmq/sdk/Error.cxx
@@ -8,8 +8,8 @@
 
 #include "Error.h"
 
-namespace fair {
-namespace mq {
+namespace fair::mq
+{
 
 const char* ErrorCategory::name() const noexcept
 {
@@ -40,5 +40,4 @@ const ErrorCategory errorCategory{};
 
 std::error_code MakeErrorCode(ErrorCode e) { return {static_cast<int>(e), errorCategory}; }
 
-}   // namespace mq
-}   // namespace fair
+} // namespace fair::mq
diff --git a/fairmq/sdk/Error.h b/fairmq/sdk/Error.h
index 5f8ae5f2..a8848b49 100644
--- a/fairmq/sdk/Error.h
+++ b/fairmq/sdk/Error.h
@@ -13,9 +13,11 @@
 #include <stdexcept>
 #include <system_error>
 
-namespace fair {
-namespace mq {
-namespace sdk {
+namespace fair::mq
+{
+
+namespace sdk
+{
 
 struct RuntimeError : ::std::runtime_error
 {
@@ -45,15 +47,15 @@ struct ErrorCategory : std::error_category
   std::string message(int ev) const override;
 };
 
-} /* namespace mq */
-} /* namespace fair */
+} // namespace fair::mq
 
-namespace std {
+namespace std
+{
 
 template<>
 struct is_error_code_enum<fair::mq::ErrorCode> : true_type
 {};
 
-}   // namespace std
+} // namespace std
 
 #endif /* FAIR_MQ_SDK_ERROR_H */
diff --git a/fairmq/sdk/Topology.cxx b/fairmq/sdk/Topology.cxx
index 597644c9..5db81dd2 100644
--- a/fairmq/sdk/Topology.cxx
+++ b/fairmq/sdk/Topology.cxx
@@ -10,9 +10,8 @@
 
 #include <dds/dds.h>
 
-namespace fair {
-namespace mq {
-namespace sdk {
+namespace fair::mq::sdk
+{
 
 /// @brief Helper to (Re)Construct a FairMQ topology based on already existing native DDS API objects
 /// @param nativeSession Existing and initialized CSession (either via create() or attach())
@@ -27,6 +26,4 @@ auto MakeTopology(dds::topology_api::CTopology nativeTopo,
     return {DDSTopo(std::move(nativeTopo), env), DDSSession(std::move(nativeSession), env), blockUntilConnected};
 }
 
-}   // namespace sdk
-}   // namespace mq
-}   // namespace fair
+} // namespace fair::mq::sdk
diff --git a/fairmq/sdk/Topology.h b/fairmq/sdk/Topology.h
index 0fc18425..f57d6220 100644
--- a/fairmq/sdk/Topology.h
+++ b/fairmq/sdk/Topology.h
@@ -48,9 +48,8 @@
 #include <utility>
 #include <vector>
 
-namespace fair {
-namespace mq {
-namespace sdk {
+namespace fair::mq::sdk
+{
 
 using DeviceId = std::string;
 using DeviceState = fair::mq::State;
@@ -1366,8 +1365,6 @@ auto MakeTopology(dds::topology_api::CTopology nativeTopo,
                   DDSEnv env = {},
                   bool blockUntilConnected = false) -> Topology;
 
-}   // namespace sdk
-}   // namespace mq
-}   // namespace fair
+} // namespace fair::mq::sdk
 
 #endif /* FAIR_MQ_SDK_TOPOLOGY_H */
diff --git a/fairmq/sdk/Traits.h b/fairmq/sdk/Traits.h
index be30115e..8c5929c7 100644
--- a/fairmq/sdk/Traits.h
+++ b/fairmq/sdk/Traits.h
@@ -13,8 +13,7 @@
 #include <asio/associated_executor.hpp>
 #include <type_traits>
 
-namespace asio {
-namespace detail {
+namespace asio::detail {
 
 /// Specialize to match our coding conventions
 template<typename T, typename Executor>
@@ -44,7 +43,6 @@ struct associated_allocator_impl<T,
     }
 };
 
-} /* namespace detail */
-} /* namespace asio */
+} /* namespace asio::detail */
 
 #endif /* FAIR_MQ_SDK_TRAITS_H */
diff --git a/fairmq/sdk/commands/Commands.cxx b/fairmq/sdk/commands/Commands.cxx
index 463a4351..6dab0e82 100644
--- a/fairmq/sdk/commands/Commands.cxx
+++ b/fairmq/sdk/commands/Commands.cxx
@@ -17,10 +17,8 @@
 
 using namespace std;
 
-namespace fair {
-namespace mq {
-namespace sdk {
-namespace cmd {
+namespace fair::mq::sdk::cmd
+{
 
 array<Result, 2> fbResultToResult =
 {
@@ -478,7 +476,4 @@ void Cmds::Deserialize(const string& str, const Format type)
     }
 }
 
-}   // namespace cmd
-}   // namespace sdk
-}   // namespace mq
-}   // namespace fair
+} // namespace fair::mq::sdk::cmd
diff --git a/fairmq/sdk/commands/Commands.h b/fairmq/sdk/commands/Commands.h
index 919ac41e..abf579a6 100644
--- a/fairmq/sdk/commands/Commands.h
+++ b/fairmq/sdk/commands/Commands.h
@@ -17,13 +17,7 @@
 #include <type_traits>
 #include <stdexcept>
 
-namespace fair
-{
-namespace mq
-{
-namespace sdk
-{
-namespace cmd
+namespace fair::mq::sdk::cmd
 {
 
 enum class Format : int {
@@ -414,9 +408,6 @@ std::string GetTypeName(const Type type);
 inline std::ostream& operator<<(std::ostream& os, const Result& result) { return os << GetResultName(result); }
 inline std::ostream& operator<<(std::ostream& os, const Type& type) { return os << GetTypeName(type); }
 
-} /* namespace cmd */
-} /* namespace sdk */
-} /* namespace mq */
-} /* namespace fair */
+} // namespace fair::mq::sdk::cmd
 
 #endif /* FAIR_MQ_SDK_COMMANDFACTORY */
diff --git a/fairmq/sdk/commands/CommandsFormatDef.h.in b/fairmq/sdk/commands/CommandsFormatDef.h.in
index a04967d1..cfadaf63 100644
--- a/fairmq/sdk/commands/CommandsFormatDef.h.in
+++ b/fairmq/sdk/commands/CommandsFormatDef.h.in
@@ -8,14 +8,11 @@
 
 #include <string>
 
-namespace fair {
-namespace mq {
-namespace sdk {
+namespace fair::mq::sdk
+{
 namespace cmd {
 
 constexpr auto commandsFormatDefFbs = R"(@commands_format_def_fbs@)";
 
 }   // namespace cmd
-}   // namespace sdk
-}   // namespace mq
-}   // namespace fair
+} // namespace fair::mq::sdk
diff --git a/fairmq/shmem/Common.h b/fairmq/shmem/Common.h
index 95d38030..4cdfd905 100644
--- a/fairmq/shmem/Common.h
+++ b/fairmq/shmem/Common.h
@@ -28,11 +28,7 @@
 #include <unistd.h>
 #include <sys/types.h>
 
-namespace fair
-{
-namespace mq
-{
-namespace shmem
+namespace fair::mq::shmem
 {
 
 struct SharedMemoryError : std::runtime_error { using std::runtime_error::runtime_error; };
@@ -293,8 +289,6 @@ struct SegmentDeallocate : public boost::static_visitor<>
     void* ptr;
 };
 
-} // namespace shmem
-} // namespace mq
-} // namespace fair
+} // namespace fair::mq::shmem
 
 #endif /* FAIR_MQ_SHMEM_COMMON_H_ */
diff --git a/fairmq/shmem/Manager.h b/fairmq/shmem/Manager.h
index a5c3283a..e35b7cb6 100644
--- a/fairmq/shmem/Manager.h
+++ b/fairmq/shmem/Manager.h
@@ -48,11 +48,7 @@
 
 #include <sys/mman.h> // mlock
 
-namespace fair
-{
-namespace mq
-{
-namespace shmem
+namespace fair::mq::shmem
 {
 
 class Manager
@@ -643,8 +639,6 @@ class Manager
     bool fThrowOnBadAlloc;
 };
 
-} // namespace shmem
-} // namespace mq
-} // namespace fair
+} // namespace fair::mq::shmem
 
 #endif /* FAIR_MQ_SHMEM_MANAGER_H_ */
diff --git a/fairmq/shmem/Message.h b/fairmq/shmem/Message.h
index 9ca5e1d2..20c78e1b 100644
--- a/fairmq/shmem/Message.h
+++ b/fairmq/shmem/Message.h
@@ -24,11 +24,7 @@
 #include <sys/types.h> // getpid
 #include <unistd.h> // pid_t
 
-namespace fair
-{
-namespace mq
-{
-namespace shmem
+namespace fair::mq::shmem
 {
 
 class Socket;
@@ -299,8 +295,6 @@ class Message final : public fair::mq::Message
     }
 };
 
-}
-}
-}
+} // namespace fair::mq::shmem
 
 #endif /* FAIR_MQ_SHMEM_MESSAGE_H_ */
diff --git a/fairmq/shmem/Monitor.cxx b/fairmq/shmem/Monitor.cxx
index 1f7a8cc8..d044310f 100644
--- a/fairmq/shmem/Monitor.cxx
+++ b/fairmq/shmem/Monitor.cxx
@@ -42,11 +42,7 @@ namespace
     volatile sig_atomic_t gSignalStatus = 0;
 }
 
-namespace fair
-{
-namespace mq
-{
-namespace shmem
+namespace fair::mq::shmem
 {
 
 void signalHandler(int signal)
@@ -575,6 +571,4 @@ Monitor::~Monitor()
     }
 }
 
-} // namespace shmem
-} // namespace mq
-} // namespace fair
+} // namespace fair::mq::shmem
diff --git a/fairmq/shmem/Monitor.h b/fairmq/shmem/Monitor.h
index 8efab7c6..558902cc 100644
--- a/fairmq/shmem/Monitor.h
+++ b/fairmq/shmem/Monitor.h
@@ -17,11 +17,7 @@
 #include <utility> // pair
 #include <vector>
 
-namespace fair
-{
-namespace mq
-{
-namespace shmem
+namespace fair::mq::shmem
 {
 
 struct SessionId
@@ -120,8 +116,6 @@ class Monitor
     std::unordered_map<std::string, std::chrono::high_resolution_clock::time_point> fDeviceHeartbeats;
 };
 
-} // namespace shmem
-} // namespace mq
-} // namespace fair
+} // namespace fair::mq::shmem
 
 #endif /* FAIR_MQ_SHMEM_MONITOR_H_ */
diff --git a/fairmq/shmem/Poller.h b/fairmq/shmem/Poller.h
index 468758fe..898942f7 100644
--- a/fairmq/shmem/Poller.h
+++ b/fairmq/shmem/Poller.h
@@ -21,9 +21,8 @@
 
 class FairMQChannel;
 
-namespace fair {
-namespace mq {
-namespace shmem {
+namespace fair::mq::shmem
+{
 
 class Poller final : public fair::mq::Poller
 {
@@ -201,8 +200,6 @@ class Poller final : public fair::mq::Poller
     std::unordered_map<std::string, int> fOffsetMap;
 };
 
-}   // namespace shmem
-}   // namespace mq
-}   // namespace fair
+} // namespace fair::mq::shmem
 
 #endif /* FAIR_MQ_SHMEM_POLLER_H_ */
diff --git a/fairmq/shmem/Region.h b/fairmq/shmem/Region.h
index a8c54095..6be11135 100644
--- a/fairmq/shmem/Region.h
+++ b/fairmq/shmem/Region.h
@@ -39,11 +39,7 @@
 #include <chrono>
 #include <ios>
 
-namespace fair
-{
-namespace mq
-{
-namespace shmem
+namespace fair::mq::shmem
 {
 
 struct Region
@@ -276,8 +272,6 @@ struct Region
     RegionBulkCallback fBulkCallback;
 };
 
-} // namespace shmem
-} // namespace mq
-} // namespace fair
+} // namespace fair::mq::shmem
 
 #endif /* FAIR_MQ_SHMEM_REGION_H_ */
diff --git a/fairmq/shmem/Socket.h b/fairmq/shmem/Socket.h
index 447d9bb6..e2dc6f4c 100644
--- a/fairmq/shmem/Socket.h
+++ b/fairmq/shmem/Socket.h
@@ -24,11 +24,7 @@
 
 class FairMQTransportFactory;
 
-namespace fair
-{
-namespace mq
-{
-namespace shmem
+namespace fair::mq::shmem
 {
 
 struct ZMsg
@@ -524,8 +520,6 @@ class Socket final : public fair::mq::Socket
     int fTimeout;
 };
 
-}
-}
-}
+} // namespace fair::mq::shmem
 
 #endif /* FAIR_MQ_SHMEM_SOCKET_H_ */
diff --git a/fairmq/shmem/TransportFactory.h b/fairmq/shmem/TransportFactory.h
index 5d61d23e..61849ecb 100644
--- a/fairmq/shmem/TransportFactory.h
+++ b/fairmq/shmem/TransportFactory.h
@@ -29,11 +29,7 @@
 #include <string>
 #include <vector>
 
-namespace fair
-{
-namespace mq
-{
-namespace shmem
+namespace fair::mq::shmem
 {
 
 class TransportFactory final : public fair::mq::TransportFactory
@@ -210,8 +206,6 @@ class TransportFactory final : public fair::mq::TransportFactory
     std::unique_ptr<Manager> fManager;
 };
 
-} // namespace shmem
-} // namespace mq
-} // namespace fair
+} // namespace fair::mq::shmem
 
 #endif /* FAIR_MQ_SHMEM_TRANSPORTFACTORY_H_ */
diff --git a/fairmq/shmem/UnmanagedRegion.h b/fairmq/shmem/UnmanagedRegion.h
index 333198a3..7c2777d3 100644
--- a/fairmq/shmem/UnmanagedRegion.h
+++ b/fairmq/shmem/UnmanagedRegion.h
@@ -20,11 +20,7 @@
 #include <cstddef> // size_t
 #include <string>
 
-namespace fair
-{
-namespace mq
-{
-namespace shmem
+namespace fair::mq::shmem
 {
 
 class Message;
@@ -68,8 +64,6 @@ class UnmanagedRegion final : public fair::mq::UnmanagedRegion
     uint16_t fRegionId;
 };
 
-}
-}
-}
+} // namespace fair::mq::shmem
 
 #endif /* FAIR_MQ_SHMEM_UNMANAGEDREGION_H_ */
diff --git a/fairmq/tools/CppSTL.h b/fairmq/tools/CppSTL.h
index 4789778b..356e9ad1 100644
--- a/fairmq/tools/CppSTL.h
+++ b/fairmq/tools/CppSTL.h
@@ -13,11 +13,7 @@
 #include <memory>
 #include <type_traits>
 
-namespace fair
-{
-namespace mq
-{
-namespace tools
+namespace fair::mq::tools
 {
 
 // provide an enum hasher to compensate std::hash not supporting enums in C++11
@@ -32,8 +28,6 @@ struct HashEnum
     }
 };
 
-} /* namespace tools */
-} /* namespace mq */
-} /* namespace fair */
+} // namespace fair::mq::tools
 
 #endif /* FAIR_MQ_TOOLS_CPPSTL_H */
diff --git a/fairmq/tools/InstanceLimit.h b/fairmq/tools/InstanceLimit.h
index ee9ed64b..5e09e9df 100644
--- a/fairmq/tools/InstanceLimit.h
+++ b/fairmq/tools/InstanceLimit.h
@@ -11,9 +11,8 @@
 
 #include "Strings.h"
 
-namespace fair {
-namespace mq {
-namespace tools {
+namespace fair::mq::tools
+{
 
 template<typename Tag, int Max>
 struct InstanceLimiter
@@ -50,8 +49,6 @@ struct InstanceLimiter
 template<typename Tag, int Max>
 int InstanceLimiter<Tag, Max>::fCount(0);
 
-} /* namespace tools */
-} /* namespace mq */
-} /* namespace fair */
+} // namespace fair::mq::tools
 
 #endif /* FAIR_MQ_TOOLS_INSTANCELIMIT_H */
diff --git a/fairmq/tools/Network.cxx b/fairmq/tools/Network.cxx
index 8c6085e2..c44cf0c9 100644
--- a/fairmq/tools/Network.cxx
+++ b/fairmq/tools/Network.cxx
@@ -33,11 +33,7 @@
 
 using namespace std;
 
-namespace fair
-{
-namespace mq
-{
-namespace tools
+namespace fair::mq::tools
 {
 
 // returns a map with network interface names as keys and their IP addresses as values
@@ -184,6 +180,4 @@ string getIpFromHostname(const string& hostname, boost::asio::io_service& ios)
     }
 }
 
-} /* namespace tools */
-} /* namespace mq */
-} /* namespace fair */
+} // namespace fair::mq::tools
diff --git a/fairmq/tools/Network.h b/fairmq/tools/Network.h
index ed45ff9e..c3868a5b 100644
--- a/fairmq/tools/Network.h
+++ b/fairmq/tools/Network.h
@@ -25,11 +25,7 @@ using io_service = class io_context;
 } // namespace asio
 } // namespace boost
 
-namespace fair
-{
-namespace mq
-{
-namespace tools
+namespace fair::mq::tools
 {
 
 struct DefaultRouteDetectionError : std::runtime_error { using std::runtime_error::runtime_error; };
@@ -47,8 +43,6 @@ std::string getIpFromHostname(const std::string& hostname);
 
 std::string getIpFromHostname(const std::string& hostname, boost::asio::io_service& ios);
 
-} /* namespace tools */
-} /* namespace mq */
-} /* namespace fair */
+} // namespace fair::mq::tools
 
 #endif /* FAIR_MQ_TOOLS_NETWORK_H */
diff --git a/fairmq/tools/Process.cxx b/fairmq/tools/Process.cxx
index 219c61a3..95eaf638 100644
--- a/fairmq/tools/Process.cxx
+++ b/fairmq/tools/Process.cxx
@@ -44,11 +44,7 @@ class LinePrinter
     const string fPrefix;
 };
 
-namespace fair
-{
-namespace mq
-{
-namespace tools
+namespace fair::mq::tools
 {
 
 /**
@@ -167,6 +163,4 @@ execute_result execute(const string& cmd, const string& prefix, const string& in
     return result;
 }
 
-} /* namespace tools */
-} /* namespace mq */
-} /* namespace fair */
+} // namespace fair::mq::tools
diff --git a/fairmq/tools/Process.h b/fairmq/tools/Process.h
index 4a96770b..839b345d 100644
--- a/fairmq/tools/Process.h
+++ b/fairmq/tools/Process.h
@@ -11,11 +11,7 @@
 
 #include <string>
 
-namespace fair
-{
-namespace mq
-{
-namespace tools
+namespace fair::mq::tools
 {
 
 /**
@@ -41,8 +37,6 @@ execute_result execute(const std::string& cmd,
                        const std::string& input = "",
                        int sig = -1);
 
-} /* namespace tools */
-} /* namespace mq */
-} /* namespace fair */
+} // namespace fair::mq::tools
 
 #endif /* FAIR_MQ_TOOLS_PROCESS_H */
diff --git a/fairmq/tools/RateLimit.h b/fairmq/tools/RateLimit.h
index 0b37b66c..cbca179c 100644
--- a/fairmq/tools/RateLimit.h
+++ b/fairmq/tools/RateLimit.h
@@ -16,11 +16,7 @@
 #include <thread>
 #include <chrono>
 
-namespace fair
-{
-namespace mq
-{
-namespace tools
+namespace fair::mq::tools
 {
 
 /**
@@ -136,8 +132,6 @@ class RateLimiter
     int skip_check_count = 1;
 };
 
-} /* namespace tools */
-} /* namespace mq */
-} /* namespace fair */
+} // namespace fair::mq::tools
 
 #endif  // FAIR_MQ_TOOLS_RATELIMIT_H
diff --git a/fairmq/tools/Semaphore.cxx b/fairmq/tools/Semaphore.cxx
index fc5c424c..07fe74fa 100644
--- a/fairmq/tools/Semaphore.cxx
+++ b/fairmq/tools/Semaphore.cxx
@@ -8,9 +8,8 @@
 
 #include "Semaphore.h"
 
-namespace fair {
-namespace mq {
-namespace tools {
+namespace fair::mq::tools
+{
 
 Semaphore::Semaphore()
     : Semaphore(0)
@@ -68,6 +67,4 @@ auto SharedSemaphore::GetCount() const -> std::size_t
     return fSemaphore->GetCount();
 }
 
-} /* namespace tools */
-} /* namespace mq */
-} /* namespace fair */
+} // namespace fair::mq::tools
diff --git a/fairmq/tools/Semaphore.h b/fairmq/tools/Semaphore.h
index 2549b65e..bf376355 100644
--- a/fairmq/tools/Semaphore.h
+++ b/fairmq/tools/Semaphore.h
@@ -15,9 +15,8 @@
 #include <memory>
 #include <mutex>
 
-namespace fair {
-namespace mq {
-namespace tools {
+namespace fair::mq::tools
+{
 
 /**
  * @struct Semaphore Semaphore.h <fairmq/tools/Semaphore.h>
@@ -55,8 +54,6 @@ private:
   std::shared_ptr<Semaphore> fSemaphore;
 };
 
-} /* namespace tools */
-} /* namespace mq */
-} /* namespace fair */
+} // namespace fair::mq::tools
 
 #endif /* FAIR_MQ_TOOLS_SEMAPHORE_H */
diff --git a/fairmq/tools/Strings.h b/fairmq/tools/Strings.h
index e2ea0efe..3080b02a 100644
--- a/fairmq/tools/Strings.h
+++ b/fairmq/tools/Strings.h
@@ -15,11 +15,7 @@
 #include <string>
 #include <vector>
 
-namespace fair
-{
-namespace mq
-{
-namespace tools
+namespace fair::mq::tools
 {
 
 /// @brief concatenates a variable number of args with the << operator via a stringstream
@@ -43,8 +39,6 @@ inline auto ToStrVector(const int argc, char*const* argv, const bool dropProgram
     }
 }
 
-} /* namespace tools */
-} /* namespace mq */
-} /* namespace fair */
+} // namespace fair::mq::tools
 
 #endif /* FAIR_MQ_TOOLS_STRINGS_H */
diff --git a/fairmq/tools/Unique.cxx b/fairmq/tools/Unique.cxx
index 1660e6dc..1a85902a 100644
--- a/fairmq/tools/Unique.cxx
+++ b/fairmq/tools/Unique.cxx
@@ -19,11 +19,7 @@
 
 using namespace std;
 
-namespace fair
-{
-namespace mq
-{
-namespace tools
+namespace fair::mq::tools
 {
 
 // generates UUID string
@@ -43,6 +39,4 @@ size_t UuidHash()
     return uuid_hasher(u);
 }
 
-} /* namespace tools */
-} /* namespace mq */
-} /* namespace fair */
+} // namespace fair::mq::tools
diff --git a/fairmq/tools/Unique.h b/fairmq/tools/Unique.h
index 42e2ed21..13696912 100644
--- a/fairmq/tools/Unique.h
+++ b/fairmq/tools/Unique.h
@@ -11,11 +11,7 @@
 
 #include <string>
 
-namespace fair
-{
-namespace mq
-{
-namespace tools
+namespace fair::mq::tools
 {
 
 // generates UUID string
@@ -24,8 +20,6 @@ std::string Uuid();
 // generates UUID and returns its hash
 std::size_t UuidHash();
 
-} /* namespace tools */
-} /* namespace mq */
-} /* namespace fair */
+} // namespace fair::mq::tools
 
 #endif /* FAIR_MQ_TOOLS_UNIQUE_H */
diff --git a/fairmq/tools/Version.h b/fairmq/tools/Version.h
index 53d3b37d..156d9f61 100644
--- a/fairmq/tools/Version.h
+++ b/fairmq/tools/Version.h
@@ -12,11 +12,7 @@
 #include <ostream>
 #include <tuple>
 
-namespace fair
-{
-namespace mq
-{
-namespace tools
+namespace fair::mq::tools
 {
 
 struct Version
@@ -32,8 +28,6 @@ struct Version
     friend auto operator<<(std::ostream& os, const Version& v) -> std::ostream& { return os << v.fkMajor << "." << v.fkMinor << "." << v.fkPatch; }
 };
 
-} /* namespace tools */
-} /* namespace mq */
-} /* namespace fair */
+} // namespace fair::mq::tools
 
 #endif /* FAIR_MQ_TOOLS_VERSION_H */
diff --git a/fairmq/zeromq/Context.h b/fairmq/zeromq/Context.h
index 2c3af60d..8443b7b2 100644
--- a/fairmq/zeromq/Context.h
+++ b/fairmq/zeromq/Context.h
@@ -25,11 +25,7 @@
 #include <thread>
 #include <vector>
 
-namespace fair
-{
-namespace mq
-{
-namespace zmq
+namespace fair::mq::zmq
 {
 
 struct ContextError : std::runtime_error { using std::runtime_error::runtime_error; };
@@ -191,8 +187,6 @@ class Context
     bool fRegionEventsSubscriptionActive;
 };
 
-}   // namespace zmq
-}   // namespace mq
-}   // namespace fair
+} // namespace fair::mq::zmq
 
 #endif /* FAIR_MQ_ZMQ_CONTEXT_H_ */
diff --git a/fairmq/zeromq/Message.h b/fairmq/zeromq/Message.h
index f56f5283..f0e3953c 100644
--- a/fairmq/zeromq/Message.h
+++ b/fairmq/zeromq/Message.h
@@ -23,11 +23,7 @@
 #include <new> // bad_alloc
 #include <string>
 
-namespace fair
-{
-namespace mq
-{
-namespace zmq
+namespace fair::mq::zmq
 {
 
 class Socket;
@@ -279,8 +275,6 @@ class Message final : public fair::mq::Message
     }
 };
 
-}   // namespace zmq
-}   // namespace mq
-}   // namespace fair
+} // namespace fair::mq::zmq
 
 #endif /* FAIR_MQ_ZMQ_MESSAGE_H */
diff --git a/fairmq/zeromq/Poller.h b/fairmq/zeromq/Poller.h
index 3edf1b32..85744261 100644
--- a/fairmq/zeromq/Poller.h
+++ b/fairmq/zeromq/Poller.h
@@ -20,11 +20,7 @@
 #include <unordered_map>
 #include <vector>
 
-namespace fair
-{
-namespace mq
-{
-namespace zmq
+namespace fair::mq::zmq
 {
 
 class Poller final : public fair::mq::Poller
@@ -204,8 +200,6 @@ class Poller final : public fair::mq::Poller
     std::unordered_map<std::string, int> fOffsetMap;
 };
 
-}   // namespace zmq
-}   // namespace mq
-}   // namespace fair
+} // namespace fair::mq::zmq
 
 #endif /* FAIR_MQ_ZMQ_POLLER_H */
diff --git a/fairmq/zeromq/Socket.h b/fairmq/zeromq/Socket.h
index 912c3640..f9ee36ff 100644
--- a/fairmq/zeromq/Socket.h
+++ b/fairmq/zeromq/Socket.h
@@ -21,9 +21,8 @@
 #include <atomic>
 #include <memory> // unique_ptr, make_unique
 
-namespace fair {
-namespace mq {
-namespace zmq {
+namespace fair::mq::zmq
+{
 
 class Socket final : public fair::mq::Socket
 {
@@ -471,8 +470,6 @@ class Socket final : public fair::mq::Socket
     int fTimeout;
 };
 
-}   // namespace zmq
-}   // namespace mq
-}   // namespace fair
+} // namespace fair::mq::zmq
 
 #endif /* FAIR_MQ_ZMQ_SOCKET_H */
diff --git a/fairmq/zeromq/TransportFactory.h b/fairmq/zeromq/TransportFactory.h
index 3ca9f516..de3eb3a5 100644
--- a/fairmq/zeromq/TransportFactory.h
+++ b/fairmq/zeromq/TransportFactory.h
@@ -21,11 +21,7 @@
 #include <string>
 #include <vector>
 
-namespace fair
-{
-namespace mq
-{
-namespace zmq
+namespace fair::mq::zmq
 {
 
 class TransportFactory final : public FairMQTransportFactory
@@ -145,8 +141,6 @@ class TransportFactory final : public FairMQTransportFactory
     std::unique_ptr<Context> fCtx;
 };
 
-}   // namespace zmq
-}   // namespace mq
-}   // namespace fair
+} // namespace fair::mq::zmq
 
 #endif /* FAIR_MQ_ZMQ_TRANSPORTFACTORY_H */
diff --git a/fairmq/zeromq/UnmanagedRegion.h b/fairmq/zeromq/UnmanagedRegion.h
index b8b3c982..201ddb43 100644
--- a/fairmq/zeromq/UnmanagedRegion.h
+++ b/fairmq/zeromq/UnmanagedRegion.h
@@ -16,11 +16,7 @@
 #include <cstddef> // size_t
 #include <string>
 
-namespace fair
-{
-namespace mq
-{
-namespace zmq
+namespace fair::mq::zmq
 {
 
 class UnmanagedRegion final : public fair::mq::UnmanagedRegion
@@ -72,8 +68,6 @@ class UnmanagedRegion final : public fair::mq::UnmanagedRegion
     RegionBulkCallback fBulkCallback;
 };
 
-}   // namespace zmq
-}   // namespace mq
-}   // namespace fair
+} // namespace fair::mq::zmq
 
 #endif /* FAIR_MQ_ZMQ_UNMANAGEDREGION_H */
diff --git a/test/device/TestReceiver.h b/test/device/TestReceiver.h
index 9a33494c..00a2f920 100644
--- a/test/device/TestReceiver.h
+++ b/test/device/TestReceiver.h
@@ -15,11 +15,7 @@
 #include <string>
 #include <thread>
 
-namespace fair
-{
-namespace mq
-{
-namespace test
+namespace fair::mq::test
 {
 
 class Receiver : public FairMQDevice
@@ -48,8 +44,6 @@ class Receiver : public FairMQDevice
     std::string fChannelName;
 };
 
-} // namespace test
-} // namespace mq
-} // namespace fair
+} // namespace fair::mq::test
 
 #endif // FAIR_MQ_TEST_TESTRECEIVER_H
diff --git a/test/device/TestSender.h b/test/device/TestSender.h
index d1cca38c..1666e6d9 100644
--- a/test/device/TestSender.h
+++ b/test/device/TestSender.h
@@ -15,11 +15,7 @@
 #include <string>
 #include <thread>
 
-namespace fair
-{
-namespace mq
-{
-namespace test
+namespace fair::mq::test
 {
 
 class Sender : public FairMQDevice
@@ -48,8 +44,6 @@ class Sender : public FairMQDevice
     std::string fChannelName;
 };
 
-} // namespace test
-} // namespace mq
-} // namespace fair
+} // namespace fair::mq::test
 
 #endif // FAIR_MQ_TEST_TESTSENDER_H
diff --git a/test/helper/devices/TestErrorState.h b/test/helper/devices/TestErrorState.h
index e7e7af78..2e89addd 100644
--- a/test/helper/devices/TestErrorState.h
+++ b/test/helper/devices/TestErrorState.h
@@ -14,11 +14,7 @@
 
 #include <iostream>
 
-namespace fair
-{
-namespace mq
-{
-namespace test
+namespace fair::mq::test
 {
 
 class ErrorState : public FairMQDevice
@@ -106,8 +102,6 @@ class ErrorState : public FairMQDevice
     }
 };
 
-} // namespace test
-} // namespace mq
-} // namespace fair
+} // namespace fair::mq::test
 
 #endif /* FAIR_MQ_TEST_ERROR_STATE_H */
diff --git a/test/helper/devices/TestExceptions.h b/test/helper/devices/TestExceptions.h
index d0a2abf4..48de0870 100644
--- a/test/helper/devices/TestExceptions.h
+++ b/test/helper/devices/TestExceptions.h
@@ -15,11 +15,7 @@
 #include <iostream>
 #include <stdexcept>
 
-namespace fair
-{
-namespace mq
-{
-namespace test
+namespace fair::mq::test
 {
 
 class Exceptions : public FairMQDevice
@@ -98,8 +94,6 @@ class Exceptions : public FairMQDevice
     }
 };
 
-} // namespace test
-} // namespace mq
-} // namespace fair
+} // namespace fair::mq::test
 
 #endif /* FAIR_MQ_TEST_EXCEPTIONS_H */
diff --git a/test/helper/devices/TestPairLeft.h b/test/helper/devices/TestPairLeft.h
index 66172de0..573f743f 100644
--- a/test/helper/devices/TestPairLeft.h
+++ b/test/helper/devices/TestPairLeft.h
@@ -14,11 +14,7 @@
 #include <cstddef>
 #include <thread>
 
-namespace fair
-{
-namespace mq
-{
-namespace test
+namespace fair::mq::test
 {
 
 class PairLeft : public FairMQDevice
@@ -61,8 +57,6 @@ class PairLeft : public FairMQDevice
     };
 };
 
-} // namespace test
-} // namespace mq
-} // namespace fair
+} // namespace fair::mq::test
 
 #endif /* FAIR_MQ_TEST_PAIRLEFT_H */
diff --git a/test/helper/devices/TestPairRight.h b/test/helper/devices/TestPairRight.h
index e23bf4c8..281e2815 100644
--- a/test/helper/devices/TestPairRight.h
+++ b/test/helper/devices/TestPairRight.h
@@ -14,11 +14,7 @@
 #include <string>
 #include <thread>
 
-namespace fair
-{
-namespace mq
-{
-namespace test
+namespace fair::mq::test
 {
 
 class PairRight : public FairMQDevice
@@ -58,8 +54,6 @@ class PairRight : public FairMQDevice
     };
 };
 
-} // namespace test
-} // namespace mq
-} // namespace fair
+} // namespace fair::mq::test
 
 #endif /* FAIR_MQ_TEST_PAIRRIGHT_H */
diff --git a/test/helper/devices/TestPollIn.h b/test/helper/devices/TestPollIn.h
index f55681b5..9c1d2354 100644
--- a/test/helper/devices/TestPollIn.h
+++ b/test/helper/devices/TestPollIn.h
@@ -14,11 +14,7 @@
 #include <fairmq/ProgOptions.h>
 #include <thread>
 
-namespace fair
-{
-namespace mq
-{
-namespace test
+namespace fair::mq::test
 {
 
 using namespace std;
@@ -123,8 +119,6 @@ class PollIn : public FairMQDevice
     int fPollType;
 };
 
-} // namespace test
-} // namespace mq
-} // namespace fair
+} // namespace fair::mq::test
 
 #endif /* FAIR_MQ_TEST_POLLIN_H */
diff --git a/test/helper/devices/TestPollOut.h b/test/helper/devices/TestPollOut.h
index 04163ce3..654a8979 100644
--- a/test/helper/devices/TestPollOut.h
+++ b/test/helper/devices/TestPollOut.h
@@ -12,11 +12,7 @@
 #include <FairMQDevice.h>
 #include <thread>
 
-namespace fair
-{
-namespace mq
-{
-namespace test
+namespace fair::mq::test
 {
 
 class PollOut : public FairMQDevice
@@ -36,8 +32,6 @@ class PollOut : public FairMQDevice
     };
 };
 
-} // namespace test
-} // namespace mq
-} // namespace fair
+} // namespace fair::mq::test
 
 #endif /* FAIR_MQ_TEST_POLLOUT_H */
diff --git a/test/helper/devices/TestPub.h b/test/helper/devices/TestPub.h
index 4bb77a6f..30054372 100644
--- a/test/helper/devices/TestPub.h
+++ b/test/helper/devices/TestPub.h
@@ -14,11 +14,7 @@
 #include <chrono>
 #include <thread>
 
-namespace fair
-{
-namespace mq
-{
-namespace test
+namespace fair::mq::test
 {
 
 class Pub : public FairMQDevice
@@ -70,8 +66,6 @@ class Pub : public FairMQDevice
     }
 };
 
-} // namespace test
-} // namespace mq
-} // namespace fair
+} // namespace fair::mq::test
 
 #endif /* FAIR_MQ_TEST_PUB_H */
diff --git a/test/helper/devices/TestPull.h b/test/helper/devices/TestPull.h
index 645c43ad..261957cf 100644
--- a/test/helper/devices/TestPull.h
+++ b/test/helper/devices/TestPull.h
@@ -13,11 +13,7 @@
 #include <FairMQLogger.h>
 #include <thread>
 
-namespace fair
-{
-namespace mq
-{
-namespace test
+namespace fair::mq::test
 {
 
 using namespace std;
@@ -41,8 +37,6 @@ class Pull : public FairMQDevice
     };
 };
 
-} // namespace test
-} // namespace mq
-} // namespace fair
+} // namespace fair::mq::test
 
 #endif /* FAIR_MQ_TEST_PULL_H */
diff --git a/test/helper/devices/TestPush.h b/test/helper/devices/TestPush.h
index f86e46dd..69cb2bfd 100644
--- a/test/helper/devices/TestPush.h
+++ b/test/helper/devices/TestPush.h
@@ -12,11 +12,7 @@
 #include <FairMQDevice.h>
 #include <thread>
 
-namespace fair
-{
-namespace mq
-{
-namespace test
+namespace fair::mq::test
 {
 
 class Push : public FairMQDevice
@@ -34,8 +30,6 @@ class Push : public FairMQDevice
     };
 };
 
-} // namespace test
-} // namespace mq
-} // namespace fair
+} // namespace fair::mq::test
 
 #endif /* FAIR_MQ_TEST_PUSH_H */
diff --git a/test/helper/devices/TestRep.h b/test/helper/devices/TestRep.h
index 9bbca15d..7159fe1b 100644
--- a/test/helper/devices/TestRep.h
+++ b/test/helper/devices/TestRep.h
@@ -13,11 +13,7 @@
 #include <FairMQLogger.h>
 #include <thread>
 
-namespace fair
-{
-namespace mq
-{
-namespace test
+namespace fair::mq::test
 {
 
 class Rep : public FairMQDevice
@@ -49,8 +45,6 @@ class Rep : public FairMQDevice
     };
 };
 
-} // namespace test
-} // namespace mq
-} // namespace fair
+} // namespace fair::mq::test
 
 #endif /* FAIR_MQ_TEST_REP_H */
diff --git a/test/helper/devices/TestReq.h b/test/helper/devices/TestReq.h
index c8c835d1..cf719f4f 100644
--- a/test/helper/devices/TestReq.h
+++ b/test/helper/devices/TestReq.h
@@ -13,11 +13,7 @@
 #include <FairMQLogger.h>
 #include <thread>
 
-namespace fair
-{
-namespace mq
-{
-namespace test
+namespace fair::mq::test
 {
 
 class Req : public FairMQDevice
@@ -41,8 +37,6 @@ class Req : public FairMQDevice
     };
 };
 
-} // namespace test
-} // namespace mq
-} // namespace fair
+} // namespace fair::mq::test
 
 #endif /* FAIR_MQ_TEST_REQ_H */
diff --git a/test/helper/devices/TestSignals.h b/test/helper/devices/TestSignals.h
index 474cb764..5cd95c59 100644
--- a/test/helper/devices/TestSignals.h
+++ b/test/helper/devices/TestSignals.h
@@ -15,11 +15,7 @@
 #include <iostream>
 #include <csignal>
 
-namespace fair
-{
-namespace mq
-{
-namespace test
+namespace fair::mq::test
 {
 
 class Signals : public FairMQDevice
@@ -105,8 +101,6 @@ class Signals : public FairMQDevice
     }
 };
 
-} // namespace test
-} // namespace mq
-} // namespace fair
+} // namespace fair::mq::test
 
 #endif /* FAIR_MQ_TEST_SIGNALS_H */
diff --git a/test/helper/devices/TestSub.h b/test/helper/devices/TestSub.h
index 893b2f44..dad14662 100644
--- a/test/helper/devices/TestSub.h
+++ b/test/helper/devices/TestSub.h
@@ -14,11 +14,7 @@
 #include <chrono>
 #include <thread>
 
-namespace fair
-{
-namespace mq
-{
-namespace test
+namespace fair::mq::test
 {
 
 class Sub : public FairMQDevice
@@ -64,8 +60,6 @@ class Sub : public FairMQDevice
     }
 };
 
-} // namespace test
-} // namespace mq
-} // namespace fair
+} // namespace fair::mq::test
 
 #endif /* FAIR_MQ_TEST_SUB_H */
diff --git a/test/helper/devices/TestTransferTimeout.h b/test/helper/devices/TestTransferTimeout.h
index b681ffe1..8e4355a4 100644
--- a/test/helper/devices/TestTransferTimeout.h
+++ b/test/helper/devices/TestTransferTimeout.h
@@ -12,11 +12,7 @@
 #include <FairMQDevice.h>
 #include <FairMQLogger.h>
 
-namespace fair
-{
-namespace mq
-{
-namespace test
+namespace fair::mq::test
 {
 
 class TransferTimeout : public FairMQDevice
@@ -156,8 +152,6 @@ class TransferTimeout : public FairMQDevice
     };
 };
 
-} // namespace test
-} // namespace mq
-} // namespace fair
+} // namespace fair::mq::test
 
 #endif /* FAIR_MQ_TEST_TRANSFERTIMEOUT_H */
diff --git a/test/helper/devices/TestWaitFor.h b/test/helper/devices/TestWaitFor.h
index b565bb3c..def2a53f 100644
--- a/test/helper/devices/TestWaitFor.h
+++ b/test/helper/devices/TestWaitFor.h
@@ -14,11 +14,7 @@
 
 #include <iostream>
 
-namespace fair
-{
-namespace mq
-{
-namespace test
+namespace fair::mq::test
 {
 
 class TestWaitFor : public FairMQDevice
@@ -55,8 +51,6 @@ class TestWaitFor : public FairMQDevice
     }
 };
 
-} // namespace test
-} // namespace mq
-} // namespace fair
+} // namespace fair::mq::test
 
 #endif /* FAIR_MQ_TEST_WAITFOR_H */
diff --git a/test/helper/plugins/dummy.h.in b/test/helper/plugins/dummy.h.in
index a8441034..ac7c4dcf 100644
--- a/test/helper/plugins/dummy.h.in
+++ b/test/helper/plugins/dummy.h.in
@@ -15,11 +15,7 @@
 #include <tuple>
 #include <vector>
 
-namespace fair
-{
-namespace mq
-{
-namespace test
+namespace fair::mq::test
 {
 
 class DummyPlugin : public fair::mq::Plugin
@@ -67,8 +63,6 @@ REGISTER_FAIRMQ_PLUGIN(
     fair::mq::test::DummyPluginProgramOptions    // Free function which declares custom program options for the plugin
 )
 
-} /* namespace test */
-} /* namespace mq */
-} /* namespace fair */
+} // namespace fair::mq::test
 
 #endif /* FAIR_MQ_TEST_PLUGIN_DUMMY */
diff --git a/test/helper/plugins/dummy2.h.in b/test/helper/plugins/dummy2.h.in
index 46d812e6..df662c37 100644
--- a/test/helper/plugins/dummy2.h.in
+++ b/test/helper/plugins/dummy2.h.in
@@ -11,11 +11,7 @@
 
 #include <fairmq/Plugin.h>
 
-namespace fair
-{
-namespace mq
-{
-namespace test
+namespace fair::mq::test
 {
 
 class Dummy2Plugin : public fair::mq::Plugin
@@ -37,8 +33,6 @@ REGISTER_FAIRMQ_PLUGIN(
     fair::mq::Plugin::NoProgramOptions
 )
 
-} /* namespace test */
-} /* namespace mq */
-} /* namespace fair */
+} // namespace fair::mq::test
 
 #endif /* FAIR_MQ_TEST_PLUGIN_DUMMY */
diff --git a/test/plugin_services/Fixture.h b/test/plugin_services/Fixture.h
index f871cad8..ca17f000 100644
--- a/test/plugin_services/Fixture.h
+++ b/test/plugin_services/Fixture.h
@@ -16,11 +16,7 @@
 #include <memory>
 #include <thread>
 
-namespace fair
-{
-namespace mq
-{
-namespace test
+namespace fair::mq::test
 {
 
 inline auto control(FairMQDevice& device) -> void
@@ -64,8 +60,6 @@ struct PluginServices : ::testing::Test {
     std::thread fRunStateMachineThread;
 };
 
-} /* namespace test */
-} /* namespace mq */
-} /* namespace fair */
+} // namespace fair::mq::test
 
 #endif /* FAIR_MQ_TEST_FIXTURE */
diff --git a/test/runner.cxx.in b/test/runner.cxx.in
index d47a1125..3119d572 100644
--- a/test/runner.cxx.in
+++ b/test/runner.cxx.in
@@ -13,11 +13,7 @@
 
 #include <string>
 
-namespace fair
-{
-namespace mq
-{
-namespace test
+namespace fair::mq::test
 {
 
 using namespace std;
@@ -25,9 +21,7 @@ using namespace std;
 string runTestDevice = "@RUN_TEST_DEVICE@";
 string mqConfig = "@MQ_CONFIG@";
 
-} /* namespace test */
-} /* namespace mq */
-} /* namespace fair */
+} // namespace fair::mq::test
 
 int main(int argc, char** argv)
 {
diff --git a/test/runner.h b/test/runner.h
index 73eada8c..8a932788 100644
--- a/test/runner.h
+++ b/test/runner.h
@@ -11,18 +11,12 @@
 
 #include <string>
 
-namespace fair
-{
-namespace mq
-{
-namespace test
+namespace fair::mq::test
 {
 
 extern std::string runTestDevice; /// Path to test device executable.
 extern std::string mqConfig; /// Path to FairMQ device config file.
 
-} /* namespace test */
-} /* namespace mq */
-} /* namespace fair */
+} // namespace fair::mq::test
 
 #endif /* FAIR_MQ_TEST_RUNNER_H */
diff --git a/test/sdk/Fixtures.h b/test/sdk/Fixtures.h
index c92ffcfc..51407b20 100644
--- a/test/sdk/Fixtures.h
+++ b/test/sdk/Fixtures.h
@@ -25,9 +25,8 @@
 #include <cstdlib>
 #include <thread>
 
-namespace fair {
-namespace mq {
-namespace test {
+namespace fair::mq::test
+{
 
 struct LoggerConfig
 {
@@ -165,9 +164,6 @@ struct AsyncOpFixture : ::testing::Test
     asio::io_context mIoContext;
 };
 
-} /* namespace test */
-} /* namespace mq */
-} /* namespace fair */
+} // namespace fair::mq::test
 
 #endif /* FAIR_MQ_TEST_FIXTURES */
-