diff --git a/src/socket_base.cpp b/src/socket_base.cpp
index 8ac39bca..39d25c42 100644
--- a/src/socket_base.cpp
+++ b/src/socket_base.cpp
@@ -434,6 +434,7 @@ int zmq::socket_base_t::connect (const char *addr_)
             id.set_flags (msg_t::identity);
             bool written = pipes [0]->write (&id);
             zmq_assert (written);
+            pipes [0]->flush ();
         }
 
         //  Attach remote end of the pipe to the peer socket. Note that peer's