diff --git a/lib/clientlib.js b/lib/clientlib.js
index 1255069..ff5affe 100644
--- a/lib/clientlib.js
+++ b/lib/clientlib.js
@@ -381,12 +381,25 @@ function normalizeAssets(clientLibPath, assets) {
       }
     });
 
+    mapping = removeDuplicates(mapping, 'src');
+
     asset.files = mapping;
   });
 
   return list;
 }
 
+/**
+ * Removes duplicates in array of Objects based on the provided key
+ * From: https://firstclassjs.com/remove-duplicate-objects-from-javascript-array-how-to-performance-comparison/
+ * @param {Array} array - array of Objects that will be filtered
+ * @param {String} key - key that will be used for filter comparison
+ */
+function removeDuplicates(array, key) {
+  let lookup = new Set();
+  return array.filter(obj => !lookup.has(obj[key]) && lookup.add(obj[key]));
+}
+
 /**
  * Process the given clientlib configuration object.
  * @param {ClientLibItem} item - clientlib configuration object
@@ -409,7 +422,7 @@ function processItem(item, options, processDone) {
     // create clientlib directory
     fse.mkdirsSync(clientLibPath);
 
-    var serializationFormat = (item.serializationFormat === SERIALIZATION_FORMAT_XML) ? SERIALIZATION_FORMAT_XML 
+    var serializationFormat = (item.serializationFormat === SERIALIZATION_FORMAT_XML) ? SERIALIZATION_FORMAT_XML
                             : (item.serializationFormat === SERIALIZATION_FORMAT_SLING_XML) ? SERIALIZATION_FORMAT_SLING_XML
                             : SERIALIZATION_FORMAT_JSON;
 
diff --git a/package-lock.json b/package-lock.json
index da3e2b7..91a2d10 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,6 +1,6 @@
 {
   "name": "aem-clientlib-generator",
-  "version": "1.6.0",
+  "version": "1.7.3",
   "lockfileVersion": 1,
   "requires": true,
   "dependencies": {
diff --git a/package.json b/package.json
index 2663d27..fc65bbf 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "aem-clientlib-generator",
-  "version": "1.7.2",
+  "version": "1.7.3",
   "description": "Creates configuration files for AEM ClientLibs and synchronizes assets.",
   "author": {
     "name": "pro!vision GmbH",
diff --git a/test/clientlib.config.js b/test/clientlib.config.js
index 127c077..1d211fb 100644
--- a/test/clientlib.config.js
+++ b/test/clientlib.config.js
@@ -99,6 +99,7 @@ module.exports = {
                     flatten: false, // remove this option if you like a flat list of files in your clientlib
                     cwd: "src/frontend/js/", // change working directory (will be stripped from destination)
                     files: [
+                        "**/app.js", // this file should be included only once
                         "**/*.js", // match all js files recursively
                         "**/*.js.map"
                     ]