diff --git a/client/DirectFB/dfreerdp.c b/client/DirectFB/dfreerdp.c
index ee23a671a..763519ec1 100644
--- a/client/DirectFB/dfreerdp.c
+++ b/client/DirectFB/dfreerdp.c
@@ -293,6 +293,7 @@ int dfreerdp_run(freerdp* instance)
 
 		max_fds = 0;
 		FD_ZERO(&rfds_set);
+		FD_ZERO(&wfds_set);
 
 		for (i = 0; i < rcount; i++)
 		{
diff --git a/client/X11/xfreerdp.c b/client/X11/xfreerdp.c
index 03a13ebe6..a57e26fc9 100644
--- a/client/X11/xfreerdp.c
+++ b/client/X11/xfreerdp.c
@@ -451,6 +451,7 @@ int xfreerdp_run(freerdp* instance)
 
 		max_fds = 0;
 		FD_ZERO(&rfds_set);
+		FD_ZERO(&wfds_set);
 
 		for (i = 0; i < rcount; i++)
 		{