diff --git a/ChangeLog b/ChangeLog
index 0ce7082fd5..1b736f2d77 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2007-12-15  Tim-Philipp Müller  <tim at centricular dot net>
+
+	* gst-libs/gst/interfaces/xoverlay.c: (gst_x_overlay_expose),
+	  (gst_x_overlay_handle_events):
+	  More guards (we don't want klass to end up being NULL).
+
 2007-12-14  Sebastian Dröge  <slomo@circular-chaos.org>
 
 	* configure.ac:
diff --git a/common b/common
index ea5f2cfab1..a00d4c1966 160000
--- a/common
+++ b/common
@@ -1 +1 @@
-Subproject commit ea5f2cfab1a164a5d285fe745343cbe0a476a904
+Subproject commit a00d4c1966aab517c2694c61d580489ebcbce448
diff --git a/gst-libs/gst/interfaces/xoverlay.c b/gst-libs/gst/interfaces/xoverlay.c
index 525529a264..f2c83191f7 100644
--- a/gst-libs/gst/interfaces/xoverlay.c
+++ b/gst-libs/gst/interfaces/xoverlay.c
@@ -232,6 +232,7 @@ gst_x_overlay_expose (GstXOverlay * overlay)
   GstXOverlayClass *klass;
 
   g_return_if_fail (overlay != NULL);
+  g_return_if_fail (GST_IS_X_OVERLAY (overlay));
 
   klass = GST_X_OVERLAY_GET_CLASS (overlay);
 
@@ -257,6 +258,7 @@ gst_x_overlay_handle_events (GstXOverlay * overlay, gboolean handle_events)
   GstXOverlayClass *klass;
 
   g_return_if_fail (overlay != NULL);
+  g_return_if_fail (GST_IS_X_OVERLAY (overlay));
 
   klass = GST_X_OVERLAY_GET_CLASS (overlay);