diff --git a/fairmq/nanomsg/FairMQSocketNN.h b/fairmq/nanomsg/FairMQSocketNN.h
index b020d380..09cb0a2f 100644
--- a/fairmq/nanomsg/FairMQSocketNN.h
+++ b/fairmq/nanomsg/FairMQSocketNN.h
@@ -16,6 +16,7 @@
 #define FAIRMQSOCKETNN_H_
 
 #include <vector>
+#include <atomic>
 
 #include "FairMQSocket.h"
 
@@ -64,10 +65,10 @@ class FairMQSocketNN : public FairMQSocket
   private:
     int fSocket;
     std::string fId;
-    unsigned long fBytesTx;
-    unsigned long fBytesRx;
-    unsigned long fMessagesTx;
-    unsigned long fMessagesRx;
+    std::atomic<unsigned long> fBytesTx;
+    std::atomic<unsigned long> fBytesRx;
+    std::atomic<unsigned long> fMessagesTx;
+    std::atomic<unsigned long> fMessagesRx;
 };
 
 #endif /* FAIRMQSOCKETNN_H_ */
diff --git a/fairmq/zeromq/FairMQSocketZMQ.h b/fairmq/zeromq/FairMQSocketZMQ.h
index 986c87ae..d0b5ea71 100644
--- a/fairmq/zeromq/FairMQSocketZMQ.h
+++ b/fairmq/zeromq/FairMQSocketZMQ.h
@@ -15,6 +15,8 @@
 #ifndef FAIRMQSOCKETZMQ_H_
 #define FAIRMQSOCKETZMQ_H_
 
+#include <atomic>
+
 #include <boost/shared_ptr.hpp>
 
 #include "FairMQSocket.h"
@@ -65,10 +67,10 @@ class FairMQSocketZMQ : public FairMQSocket
   private:
     void* fSocket;
     std::string fId;
-    unsigned long fBytesTx;
-    unsigned long fBytesRx;
-    unsigned long fMessagesTx;
-    unsigned long fMessagesRx;
+    std::atomic<unsigned long> fBytesTx;
+    std::atomic<unsigned long> fBytesRx;
+    std::atomic<unsigned long> fMessagesTx;
+    std::atomic<unsigned long> fMessagesRx;
 
     static boost::shared_ptr<FairMQContextZMQ> fContext;
 };