diff --git a/Makefile b/Makefile
index 4e26a3c..209fa95 100644
--- a/Makefile
+++ b/Makefile
@@ -24,12 +24,14 @@ less:
 	@@mkdir -p dist
 	@@touch ${DIST}
 	@@cat ${HEADER} | sed s/@VERSION/${VERSION}/ > ${DIST}
+	@@echo "(function (window, undefined) {" >> ${DIST}
 	@@cat build/ecma-5.js\
 	      ${SRC}/parser.js\
 	      ${SRC}/functions.js\
 	      ${SRC}/tree/*.js\
 	      ${SRC}/tree.js\
 	      ${SRC}/browser.js >> ${DIST}
+	@@echo "})(window);" >> ${DIST}
 	@@echo ${DIST} built.
 
 min: less
diff --git a/lib/less/browser.js b/lib/less/browser.js
index d60bc76..097512c 100644
--- a/lib/less/browser.js
+++ b/lib/less/browser.js
@@ -1,4 +1,6 @@
-(function () {
+//
+// browser.js - client-side engine
+//
 
 var isFileProtocol = location.protocol === 'file:';
 
@@ -292,4 +294,3 @@ less.Parser.importer = function (path, paths, callback) {
     });
 };
 
-})();