diff --git a/inc/Action/Diff.php b/inc/Action/Diff.php
index 59ce156aef12ab6a60e2d4e7501501ff2bb0b3b6..0ced9d8246ba6d692bd9af871958aab226e570df 100644
--- a/inc/Action/Diff.php
+++ b/inc/Action/Diff.php
@@ -16,6 +16,7 @@ class Diff extends AbstractAction {
         return AUTH_READ;
     }
 
+    /** @inheritdoc */
     public function preProcess() {
         global $INPUT;
 
@@ -26,4 +27,9 @@ class Diff extends AbstractAction {
         }
     }
 
+    /** @inheritdoc */
+    public function tplContent() {
+        html_diff();
+    }
+
 }