diff --git a/tests/test_srcfd.cpp b/tests/test_srcfd.cpp
index c219fb3a..fa16256f 100644
--- a/tests/test_srcfd.cpp
+++ b/tests/test_srcfd.cpp
@@ -62,6 +62,7 @@ int main (void)
     assert (rc == 0);
 
     char tmp[MSG_SIZE];
+    memset (tmp, 0, MSG_SIZE);
     zmq_send(req, tmp, MSG_SIZE, 0);
 
     zmq_msg_t msg;