diff --git a/NEWS b/NEWS
index ca563536e717f9..daaacf94d98f92 100644
--- a/NEWS
+++ b/NEWS
@@ -14,6 +14,8 @@ with all sufficient information, see the ChangeLog file or Redmine
 
 === Language changes
 
+* Top-level constant look-up is removed.  [Feature #11547]
+
 === Core classes updates (outstanding ones only)
 
 === Stdlib updates (outstanding ones only)
diff --git a/variable.c b/variable.c
index 91482e9d0fef38..70a28a670f4175 100644
--- a/variable.c
+++ b/variable.c
@@ -2273,8 +2273,12 @@ rb_const_search(VALUE klass, ID id, int exclude, int recurse, int visibility)
 		continue;
 	    }
 	    if (exclude && tmp == rb_cObject && klass != rb_cObject) {
+#if 0
 		rb_warn("toplevel constant %"PRIsVALUE" referenced by %"PRIsVALUE"::%"PRIsVALUE"",
 			QUOTE_ID(id), rb_class_name(klass), QUOTE_ID(id));
+#else
+		return Qundef;
+#endif
 	    }
 	    return value;
 	}