diff --git a/fairmq/sdk/Topology.h b/fairmq/sdk/Topology.h
index 0068f006..6020f82f 100644
--- a/fairmq/sdk/Topology.h
+++ b/fairmq/sdk/Topology.h
@@ -183,6 +183,7 @@ class BasicTopology : public AsioBase<Executor, Allocator>
 
     ~BasicTopology()
     {
+        std::lock_guard<std::mutex> lk(fMtx);
         fDDSSession.UnsubscribeFromCommands();
         try {
             fChangeStateOp.Cancel(fState);