diff --git a/test/built-ins/Error/15.11-1.js b/test/built-ins/Error/15.11-1.js
deleted file mode 100644
index d66d5dc5fa2d1725515beb604e2bf6dc81984de4..0000000000000000000000000000000000000000
--- a/test/built-ins/Error/15.11-1.js
+++ /dev/null
@@ -1,9 +0,0 @@
-// Copyright (c) 2012 Ecma International.  All rights reserved.
-// This code is governed by the BSD license found in the LICENSE file.
-
-/*---
-es5id: 15.11-1
-description: Error - ConversionError has been removed from IE9 standard mode
----*/
-
-assert.sameValue(typeof ConversionError, "undefined", 'typeof ConversionError');
diff --git a/test/built-ins/Error/15.11-2.js b/test/built-ins/Error/15.11-2.js
deleted file mode 100644
index 4bb74dd4e5b22b7148f75c85fa404fd0bd26cdb8..0000000000000000000000000000000000000000
--- a/test/built-ins/Error/15.11-2.js
+++ /dev/null
@@ -1,9 +0,0 @@
-// Copyright (c) 2012 Ecma International.  All rights reserved.
-// This code is governed by the BSD license found in the LICENSE file.
-
-/*---
-es5id: 15.11-2
-description: Error - RegExpError has been removed from IE9 standard mode
----*/
-
-assert.sameValue(typeof RegExpError, "undefined", 'typeof RegExpError');