diff --git a/lib/compress.js b/lib/compress.js
index f28329dd..bd76e58d 100644
--- a/lib/compress.js
+++ b/lib/compress.js
@@ -1667,13 +1667,11 @@ merge(Compressor.prototype, {
         });
         var object_fns = [
             'constructor',
-            'toLocaleString',
             'toString',
             'valueOf',
         ];
         var native_fns = {
             Array: makePredicate([
-                'concat',
                 'indexOf',
                 'join',
                 'lastIndexOf',
@@ -1703,7 +1701,6 @@ merge(Compressor.prototype, {
                 'italics',
                 'lastIndexOf',
                 'link',
-                'localeCompare',
                 'match',
                 'replace',
                 'search',
@@ -1715,8 +1712,6 @@ merge(Compressor.prototype, {
                 'substr',
                 'substring',
                 'sup',
-                'toLocaleLowerCase',
-                'toLocaleUpperCase',
                 'trim',
             ].concat(object_fns)),
         };