diff --git a/cogl/cogl/cogl-object.c b/cogl/cogl/cogl-object.c
index 1b849d58c..e159c6c3a 100644
--- a/cogl/cogl/cogl-object.c
+++ b/cogl/cogl/cogl-object.c
@@ -109,7 +109,11 @@ _cogl_object_default_unref (void *object)
 void
 cogl_object_unref (void *obj)
 {
-  void (* unref_func) (void *) = ((CoglObject *) obj)->klass->virt_unref;
+  void (* unref_func) (void *);
+
+  _COGL_RETURN_IF_FAIL (obj != NULL);
+
+  unref_func = ((CoglObject *) obj)->klass->virt_unref;
   unref_func (obj);
 }