diff --git a/lib/less/index.js b/lib/less/index.js
index 62403bd0..bc3562ee 100644
--- a/lib/less/index.js
+++ b/lib/less/index.js
@@ -40,13 +40,13 @@ module.exports = function(environment, fileManagers) {
         /* eslint guard-for-in: 0 */
         t = initial.tree[n];
         if (typeof t === "function") {
-            api[n] = ctor(t);
+            api[n.toLowerCase()] = ctor(t);
         }
         else {
             api[n] = Object.create(null);
             for (var o in t) {
                 /* eslint guard-for-in: 0 */
-                api[n][o] = ctor(t[o]);
+                api[n][o.toLowerCase()] = ctor(t[o]);
             }
         }
     }