diff --git a/lib/ace/mode/powershell_highlight_rules.js b/lib/ace/mode/powershell_highlight_rules.js
index 2703d8b7..5c5bcbf4 100644
--- a/lib/ace/mode/powershell_highlight_rules.js
+++ b/lib/ace/mode/powershell_highlight_rules.js
@@ -11,11 +11,6 @@ var PowershellHighlightRules = function() {
       ("function|if|else|elseif|switch|while|default|for|do|until|break|continue|foreach|return|filter|in|trap|throw|param|begin|process|end").split("|")
     );
 
-    var buildinConstants = lang.arrayToMap(
-        ("$Null|$True|$False").split("|")
-    );
-
-
     // regexp must not have capturing parentheses. Use (?:) instead.
     // regexps are ordered -> the first match is used
 
@@ -24,9 +19,6 @@ var PowershellHighlightRules = function() {
             {
                 token : "comment",
                 regex : "#.*$"
-            }, {
-                token : "string.regexp",
-                regex : "[/](?:(?:\\[(?:\\\\]|[^\\]])+\\])|(?:\\\\/|[^\\]/]))*[/]\\w*\\s*(?=[).,;]|$)"
             }, {
                 token : "string", // single line
                 regex : '["](?:(?:\\\\.)|(?:[^"\\\\]))*?["]'
@@ -41,15 +33,14 @@ var PowershellHighlightRules = function() {
                 regex : "[+-]?\\d+(?:(?:\\.\\d*)?(?:[eE][+-]?\\d+)?)?\\b"
             }, {
                 token : "constant.language.boolean",
-                regex : "(?:true|false)\\b"
+                regex : "[$](?:[Tt]rue|[Ff]alse)\\b"
+            }, {
+                token : "constant.language.boolean",
+                regex : "[$][Nn]ull\\b"
             }, {
                 token : function(value) {
-                    if (value == "this")
-                        return "variable.language";
-                    else if (keywords.hasOwnProperty(value))
+                    if (keywords.hasOwnProperty(value))
                         return "keyword";
-                    else if (buildinConstants.hasOwnProperty(value))
-                        return "constant.language";
                     else
                         return "identifier";
                 },