diff --git a/mono/metadata/ChangeLog b/mono/metadata/ChangeLog
index 660ad249d9151..cbc445e017c15 100644
--- a/mono/metadata/ChangeLog
+++ b/mono/metadata/ChangeLog
@@ -1,3 +1,9 @@
+2007-08-08  Massimiliano Mantione  <massi@ximian.com>
+
+	* class.c (mono_class_setup_vtable_general): Fixed bug #77127,
+	checking that methods with the same fqname are not overridden
+	with a method from an ancestor.
+
 2007-08-07  Zoltan Varga  <vargaz@gmail.com>
 
 	* threads.c (free_thread_static_data_helper): Avoid a crash if
diff --git a/mono/metadata/class.c b/mono/metadata/class.c
index 5951daa6b6c5f..f34142c20cf97 100644
--- a/mono/metadata/class.c
+++ b/mono/metadata/class.c
@@ -2018,7 +2018,8 @@ mono_class_setup_vtable_general (MonoClass *class, MonoMethod **overrides, int o
 							continue;
 
 						if (((fqname && !strcmp (cm->name, fqname)) || !strcmp (cm->name, qname)) &&
-						    mono_metadata_signature_equal (mono_method_signature (cm), mono_method_signature (im))) {
+								mono_metadata_signature_equal (mono_method_signature (cm), mono_method_signature (im)) &&
+								((vtable [io + l] == NULL) || mono_class_is_subclass_of (cm->klass, vtable [io + l]->klass, FALSE))) {
 
 							/* CAS - SecurityAction.InheritanceDemand on interface */
 							if (security_enabled && (im->flags & METHOD_ATTRIBUTE_HAS_SECURITY)) {