--- gtkentrycompletion.c.0	2011-02-19 09:31:37.000000000 -0500
+++ gtkentrycompletion.c	2011-05-13 10:27:13.027240267 -0400
@@ -1168,6 +1168,7 @@
   gchar *tmp;
 
   g_return_if_fail (GTK_IS_ENTRY_COMPLETION (completion));
+  g_return_if_fail (GTK_IS_ENTRY (completion->priv->entry));
 
   if (!completion->priv->filter_model)
     return;
