diff --git a/src/Plugin/CKEditorPlugin/ColorButton.php b/src/Plugin/CKEditorPlugin/ColorButton.php
index e93534f..690ec06 100644
--- a/src/Plugin/CKEditorPlugin/ColorButton.php
+++ b/src/Plugin/CKEditorPlugin/ColorButton.php
@@ -32,7 +32,7 @@ class ColorButton extends CKEditorPluginBase implements CKEditorPluginConfigurab
    * {@inheritdoc}
    */
   public function getFile() {
-    return '/libraries/colorbutton/plugin.js';
+    return base_path() . '/libraries/colorbutton/plugin.js';
   }
 
   /**