diff --git a/lib/formatValues.js b/lib/formatValues.js
index c23ace3..8e5bbb4 100644
--- a/lib/formatValues.js
+++ b/lib/formatValues.js
@@ -5,7 +5,7 @@ var formatShorthand = require('./formatShorthand')
 var getProperty =  require('./util').getProperty
 
 function formatvalues (decl, stylelint) {
-  var isDataUrl = /data:.+\/(.+);base64,(.*)/.test(decl.value)
+  var isDataUrl = /data:.+\/(.+),(.*)/.test(decl.value)
   var isVarNotation = /var\s*\(.*\)/.test(decl.value)
   var isString = /^("|').*("|')$/.test(decl.value)
   var isFunctionCall = /\w+\(.+\)/.test(decl.value)