diff --git a/gtk/gtkimcontextsimple.c b/gtk/gtkimcontextsimple.c
index a68886f9a9..68f7578363 100644
--- a/gtk/gtkimcontextsimple.c
+++ b/gtk/gtkimcontextsimple.c
@@ -746,7 +746,7 @@ no_sequence_matches (GtkIMContextSimple *context_simple,
 	}
   
       ch = gdk_keyval_to_unicode (event->keyval);
-      if (ch != 0)
+      if (ch != 0 && !g_unichar_iscntrl (ch))
 	{
 	  gtk_im_context_simple_commit_char (context, ch);
 	  return TRUE;
diff --git a/gtk/gtkimmulticontext.c b/gtk/gtkimmulticontext.c
index f2454fcb4a..ea471a8aaf 100644
--- a/gtk/gtkimmulticontext.c
+++ b/gtk/gtkimmulticontext.c
@@ -355,7 +355,7 @@ gtk_im_multicontext_filter_keypress (GtkIMContext *context,
       gunichar ch;
 
       ch = gdk_keyval_to_unicode (event->keyval);
-      if (ch != 0)
+      if (ch != 0 && !g_unichar_iscntrl (ch))
         {
           gint len;
           gchar buf[10];