diff --git a/src/languages/css.js b/src/languages/css.js
index 5927c9920b..e1c5bdf121 100644
--- a/src/languages/css.js
+++ b/src/languages/css.js
@@ -25,6 +25,10 @@ export default function(hljs) {
     hljs.APOS_STRING_MODE,
     hljs.QUOTE_STRING_MODE
   ];
+  const CSS_VARIABLE = {
+    className: "variable",
+    begin: /--[A-Za-z_-](?:(?!\s)[A-Za-z0-9_-])*/,
+  };
 
   return {
     name: 'CSS',
@@ -72,6 +76,7 @@ export default function(hljs) {
       //   end: /\)/,
       //   contains: [ hljs.CSS_NUMBER_MODE ]
       // },
+      CSS_VARIABLE,
       {
         className: 'attribute',
         begin: '\\b(' + css.ATTRIBUTES.join('|') + ')\\b'
@@ -106,7 +111,11 @@ export default function(hljs) {
               }
             ]
           },
-          FUNCTION_DISPATCH
+          FUNCTION_DISPATCH,
+          {
+            begin: /\(/,
+            contains: [ CSS_VARIABLE ],
+          }
         ]
       },
       {