diff --git a/x11-toolkits/gtk-sharp20/files/patch-gdk_glue_windowmanager.c b/x11-toolkits/gtk-sharp20/files/patch-gdk_glue_windowmanager.c
new file mode 100644
index 000000000000..2550cba46750
--- /dev/null
+++ b/x11-toolkits/gtk-sharp20/files/patch-gdk_glue_windowmanager.c
@@ -0,0 +1,11 @@
+--- gdk/glue/windowmanager.c.orig	2016-09-22 10:17:18 UTC
++++ gdk/glue/windowmanager.c
+@@ -110,7 +110,7 @@ gtksharp_get_gdk_net_client_list (int *count)
+ 	list = g_malloc (*count * sizeof (gpointer));
+ 	/* Put all of the windows into a GList to return */
+ 	for (i = 0; i < *count; i ++) {
+-		list [i] = data [i];
++		list [i] = (gpointer) data [i];
+ 		g_message ("WinID: %d", list [i]);
+ 	}
+