diff --git a/lib/ace/mode/sqlserver_highlight_rules.js b/lib/ace/mode/sqlserver_highlight_rules.js
index df6c9b4b..7dd1df33 100644
--- a/lib/ace/mode/sqlserver_highlight_rules.js
+++ b/lib/ace/mode/sqlserver_highlight_rules.js
@@ -45,6 +45,8 @@ var SqlServerHighlightRules = function() {
     
     // https://msdn.microsoft.com/en-us/library/ms189773.aspx
     var logicalOperators = "ALL|AND|ANY|BETWEEN|EXISTS|IN|LIKE|NOT|OR|SOME";
+    logicalOperators+= "|NULL";//SSMS colors this gray too
+    
     
     
     // multiple pages for built in functions, the following code works for all