diff --git a/tasks/includeSource.js b/tasks/includeSource.js
index d16d17f..2874dc0 100644
--- a/tasks/includeSource.js
+++ b/tasks/includeSource.js
@@ -287,6 +287,18 @@ module.exports = function(grunt) {
 
 			grunt.log.debug('Found ' + includes.length + ' include statement(s).');
 
+			//backport of array includes
+			function arrayIncludes(a, obj) {
+			    for (var i = 0; i < a.length; i++) {
+			        if (a[i] === obj) {
+			            return true;
+			        }
+			    }
+			    return false;
+			}
+
+			
+			var allFiles=[];
 			includes.forEach(function(include, includeIndex) {
 				var files = [];
 				var baseUrl;
@@ -297,6 +309,18 @@ module.exports = function(grunt) {
 				}
 				orderFiles(files, include.options);
 
+
+				//removes duplicated entry in the filelist
+				if(options.unique)
+				{
+					files = files.filter( function( afile ) {
+	  					return !arrayIncludes(allFiles, afile );
+					} );
+
+					allFiles = allFiles.concat(files);
+				}
+
+
 				if(include.options.baseUrl) {
 					baseUrl = grunt.config.process(include.options.baseUrl);
 				} else {