diff --git a/MMM-pages.js b/MMM-pages.js
index 7e8bdc1..3ef9fdd 100644
--- a/MMM-pages.js
+++ b/MMM-pages.js
@@ -197,7 +197,7 @@ Module.register('MMM-pages', {
    * Optional and only used when we want to switch to a hidden page
    */
   animatePageChange: function (targetPageName) {
-    let lockStringObj = { lockString: self.identifier };
+    let lockStringObj = { lockString: this.identifier };
     if (!this.config.useLockString) {
       // Passing in an undefined object is equivalent to not passing it in at
       // all, effectively providing only one arg to the hide and show calls