diff --git a/fairmq/shmem/Manager.h b/fairmq/shmem/Manager.h
index 24728d52a..a1dd43221 100644
--- a/fairmq/shmem/Manager.h
+++ b/fairmq/shmem/Manager.h
@@ -101,6 +101,7 @@ class Manager
         }
 
         if (autolaunchMonitor) {
+            boost::interprocess::scoped_lock<boost::interprocess::named_mutex> lock(fShmMtx);
             StartMonitor(fShmId);
         }