diff --git a/src/app/services/graphite/lexer.js b/src/app/services/graphite/lexer.js
index b0668f45628..b4cb8a0e21e 100644
--- a/src/app/services/graphite/lexer.js
+++ b/src/app/services/graphite/lexer.js
@@ -120,8 +120,9 @@ define([
       i === 36 ||           // $
       i >= 65 && i <= 90 || // A-Z
       i === 95 ||           // _
-      i === 45 ||          // -
-      i === 42 ||         // *
+      i === 45 ||           // -
+      i === 42 ||           // *
+      i === 58 ||           // :
       i >= 97 && i <= 122;  // a-z
   }