diff --git a/js/common/bootstrap/modules/internal.js b/js/common/bootstrap/modules/internal.js
index aad7e1c2a6..6ece8e5078 100644
--- a/js/common/bootstrap/modules/internal.js
+++ b/js/common/bootstrap/modules/internal.js
@@ -1726,6 +1726,10 @@ if (typeof SYS_OPTIONS !== 'undefined') {
   delete global.SYS_OPTIONS;
 }
 
+exports.propertyKeys = (obj) => Object.keys(obj).filter((key) => {
+  return (key.charAt(0) !== '_' && key.charAt(0) !== '$');
+});
+
 
 ////////////////////////////////////////////////////////////////////////////////
 /// @brief print
diff --git a/js/common/bootstrap/monkeypatches.js b/js/common/bootstrap/monkeypatches.js
index 78d2e70b57..3b2cb12833 100644
--- a/js/common/bootstrap/monkeypatches.js
+++ b/js/common/bootstrap/monkeypatches.js
@@ -38,26 +38,12 @@
 
 Object.defineProperty(Object.prototype, '_shallowCopy', {
   get() {
-    var self = this;
-    return this.propertyKeys.reduce(function (previous, key) {
-      previous[key] = self[key];
+    return require('internal').propertyKeys(this).reduce((previous, key) => {
+      previous[key] = this[key];
       return previous;
     }, {});
   }
 });
 
-////////////////////////////////////////////////////////////////////////////////
-/// @brief returns the property keys
-////////////////////////////////////////////////////////////////////////////////
-
-Object.defineProperty(Object.prototype, 'propertyKeys', {
-  get() {
-    return Object.keys(this).filter(function (key) {
-      return (key.charAt(0) !== '_' && key.charAt(0) !== '$');
-    });
-  }
-});
-
-
 }());
 
diff --git a/js/common/modules/@arangodb/graph-common.js b/js/common/modules/@arangodb/graph-common.js
index 9ea7fb619c..b7b7ca848a 100644
--- a/js/common/modules/@arangodb/graph-common.js
+++ b/js/common/modules/@arangodb/graph-common.js
@@ -28,6 +28,7 @@
 ////////////////////////////////////////////////////////////////////////////////
 
 var is = require("@arangodb/is"),
+  internal = require("internal"),
   Edge,
   Graph,
   Vertex,
@@ -244,7 +245,7 @@ Edge.prototype.getProperty = function (name) {
 ////////////////////////////////////////////////////////////////////////////////
 
 Edge.prototype.getPropertyKeys = function () {
-  return this._properties.propertyKeys;
+  return internal.propertyKeys(this._properties);
 };
 
 ////////////////////////////////////////////////////////////////////////////////
@@ -431,7 +432,7 @@ Vertex.prototype.getProperty = function (name) {
 ////////////////////////////////////////////////////////////////////////////////
 
 Vertex.prototype.getPropertyKeys = function () {
-  return this._properties.propertyKeys;
+  return internal.propertyKeys(this._properties);
 };
 
 ////////////////////////////////////////////////////////////////////////////////