diff --git a/fairmq/shmem/Common.h b/fairmq/shmem/Common.h
index 45d2dfa0..e304b9fa 100644
--- a/fairmq/shmem/Common.h
+++ b/fairmq/shmem/Common.h
@@ -12,7 +12,6 @@
 
 #include <atomic>
 #include <string>
-#include <unordered_map>
 
 #include <boost/interprocess/managed_shared_memory.hpp>
 #include <boost/interprocess/allocators/allocator.hpp>
@@ -113,8 +112,11 @@ struct RegionBlock
 inline std::string buildShmIdFromSessionIdAndUserId(const std::string& sessionId)
 {
     std::string seed((std::to_string(geteuid()) + sessionId));
-    std::string shmId = picosha2::hash256_hex_string(seed);
-    shmId.resize(10, '_');
+    // generate a 8-digit hex value out of sha256 hash
+    std::vector<unsigned char> hash(4);
+    picosha2::hash256(seed.begin(), seed.end(), hash.begin(), hash.end());
+    std::string shmId = picosha2::bytes_to_hex_string(hash.begin(), hash.end());
+
     return shmId;
 }
 
diff --git a/fairmq/shmem/TransportFactory.h b/fairmq/shmem/TransportFactory.h
index 4066a892..3808e6a0 100644
--- a/fairmq/shmem/TransportFactory.h
+++ b/fairmq/shmem/TransportFactory.h
@@ -57,7 +57,7 @@ class TransportFactory final : public fair::mq::TransportFactory
 
         int numIoThreads = 1;
         std::string sessionName = "default";
-        size_t segmentSize = 2000000000;
+        size_t segmentSize = 2ULL << 30;
         bool autolaunchMonitor = false;
         bool throwOnBadAlloc = true;
         if (config) {
@@ -71,6 +71,7 @@ class TransportFactory final : public fair::mq::TransportFactory
         }
 
         fShmId = buildShmIdFromSessionIdAndUserId(sessionName);
+        LOG(debug) << "Generated shmid '" << fShmId << "' out of session id '" << sessionName << "'.";
 
         try {
             if (zmq_ctx_set(fZMQContext, ZMQ_IO_THREADS, numIoThreads) != 0) {