diff --git a/lib/ace/mode/powershell_highlight_rules.js b/lib/ace/mode/powershell_highlight_rules.js
index 5c5bcbf4..7681044d 100644
--- a/lib/ace/mode/powershell_highlight_rules.js
+++ b/lib/ace/mode/powershell_highlight_rules.js
@@ -35,8 +35,11 @@ var PowershellHighlightRules = function() {
                 token : "constant.language.boolean",
                 regex : "[$](?:[Tt]rue|[Ff]alse)\\b"
             }, {
-                token : "constant.language.boolean",
+                token : "constant.language",
                 regex : "[$][Nn]ull\\b"
+            }, {
+                token : "variable.instance",
+                regex : "[$][a-zA-Z][a-zA-Z0-9_]*\\b"
             }, {
                 token : function(value) {
                     if (keywords.hasOwnProperty(value))