diff --git a/lib/ace/mode/javascript_highlight_rules.js b/lib/ace/mode/javascript_highlight_rules.js
index 46306409..5fc05192 100644
--- a/lib/ace/mode/javascript_highlight_rules.js
+++ b/lib/ace/mode/javascript_highlight_rules.js
@@ -80,6 +80,8 @@ var JavaScriptHighlightRules = function() {
         ("__parent__|__count__|escape|unescape|with|__proto__").split("|")
     );
 
+    var definitions = lang.arrayToMap(("const|let|var|function").split("|"));
+
     var buildinConstants = lang.arrayToMap(
         ("null|Infinity|NaN|undefined").split("|")
     );
@@ -134,7 +136,7 @@ var JavaScriptHighlightRules = function() {
                 token : "constant.numeric", // float
                 regex : "[+-]?\\d+(?:(?:\\.\\d*)?(?:[eE][+-]?\\d+)?)?\\b"
             }, {
-                token : ["keyword", "text", "entity.name.function"],
+                token : ["keyword.definition", "text", "entity.name.function"],
                 regex : "(function)(\\s+)(" + identifierRe + ")"
             }, {
                 token : "constant.language.boolean",
@@ -149,6 +151,8 @@ var JavaScriptHighlightRules = function() {
                         return "variable.language";
                     else if (deprecated.hasOwnProperty(value))
                         return "invalid.deprecated";
+                    else if (definitions.hasOwnProperty(value))
+                        return "keyword.definition";
                     else if (keywords.hasOwnProperty(value))
                         return "keyword";
                     else if (buildinConstants.hasOwnProperty(value))