diff --git a/lib/ace/mode/javascript_highlight_rules.js b/lib/ace/mode/javascript_highlight_rules.js
index 185b40d7..0571c342 100644
--- a/lib/ace/mode/javascript_highlight_rules.js
+++ b/lib/ace/mode/javascript_highlight_rules.js
@@ -154,6 +154,9 @@ var JavaScriptHighlightRules = function() {
         // makes sure we don't mix up regexps with the divison operator
         "regex_allowed": [
             {
+                token : "comment",
+                regex : "\\/\\/.*$"
+            }, {
                 token: "string.regexp",
                 regex: "\\/(?:(?:\\[(?:\\\\]|[^\\]])+\\])"
                     + "|(?:\\\\/|[^\\]/]))*" 
diff --git a/lib/ace/mode/javascript_tokenizer_test.js b/lib/ace/mode/javascript_tokenizer_test.js
index 3aa4aaa9..311fb7e8 100644
--- a/lib/ace/mode/javascript_tokenizer_test.js
+++ b/lib/ace/mode/javascript_tokenizer_test.js
@@ -142,6 +142,14 @@ module.exports = {
     "test tokenize identifier with umlauts": function() {
         var tokens = this.tokenizer.getLineTokens("füße", "start").tokens;
         assert.equal(1, tokens.length);
+    },
+    
+    "test // is not a regexp": function() {
+        var tokens = this.tokenizer.getLineTokens("{ // 123", "start").tokens;
+        assert.equal(3, tokens.length);
+        assert.equal("lparen", tokens[0].type);
+        assert.equal("text", tokens[1].type);
+        assert.equal("comment", tokens[2].type);
     }
 };