diff --git a/ChangeLog b/ChangeLog
index 9aec88d019..6177f568c0 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Mon Oct 24 10:49:50 2016  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* class.c (rb_undef_methods_from): undefine methods defined in
+	  super from klass.
+
 Mon Oct 24 10:19:44 2016  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* complex.c (Init_Complex): undefine Complex#clamp, which does not
diff --git a/class.c b/class.c
index 8a3a708686..d1a13798c2 100644
--- a/class.c
+++ b/class.c
@@ -1528,6 +1528,23 @@ rb_undef_method(VALUE klass, const char *name)
     rb_add_method(klass, rb_intern(name), VM_METHOD_TYPE_UNDEF, 0, METHOD_VISI_UNDEF);
 }
 
+static enum rb_id_table_iterator_result
+undef_method_i(ID name, VALUE value, void *data)
+{
+    VALUE klass = (VALUE)data;
+    rb_add_method(klass, name, VM_METHOD_TYPE_UNDEF, 0, METHOD_VISI_UNDEF);
+    return ID_TABLE_CONTINUE;
+}
+
+void
+rb_undef_methods_from(VALUE klass, VALUE super)
+{
+    struct rb_id_table *mtbl = RCLASS_M_TBL(super);
+    if (mtbl) {
+	rb_id_table_foreach(mtbl, undef_method_i, (void *)klass);
+    }
+}
+
 /*!
  * \}
  */
diff --git a/internal.h b/internal.h
index de435ac16b..116654ef91 100644
--- a/internal.h
+++ b/internal.h
@@ -931,6 +931,7 @@ VALUE rb_singleton_class_get(VALUE obj);
 void Init_class_hierarchy(void);
 
 int rb_class_has_methods(VALUE c);
+void rb_undef_methods_from(VALUE klass, VALUE super);
 
 /* compar.c */
 VALUE rb_invcmp(VALUE, VALUE);