diff --git a/src/lb.cpp b/src/lb.cpp
index 2787739e..c4a69178 100644
--- a/src/lb.cpp
+++ b/src/lb.cpp
@@ -137,7 +137,9 @@ int zmq::lb_t::sendpipe (msg_t *msg_, pipe_t **pipe_)
     more = msg_->flags () & msg_t::more? true: false;
     if (!more) {
         pipes [current]->flush ();
-        current = (current + 1) % active;
+
+        if (++current >= active)
+            current = 0;
     }
 
     //  Detach the message from the data buffer.