diff --git a/plugins/modules/config.py b/plugins/modules/config.py
index 9b9bbf9..865f2b9 100644
--- a/plugins/modules/config.py
+++ b/plugins/modules/config.py
@@ -128,9 +128,9 @@ def iter_system(module, result, tree=None, value=None):
         result['changed'] = True
         stjoined = ' => '.join(subtree)
         if old_value is not None:
-            result['diff'][0]['before'] += 'system => {} => {}\n'.format(app, stjoined, old_value)
+            result['diff'][0]['before'] += 'system => {} => {}\n'.format(stjoined, old_value)
         if v is not None:
-            result['diff'][0]['after'] += 'system => {} => {}\n'.format(app, stjoined, v)
+            result['diff'][0]['after'] += 'system => {} => {}\n'.format(stjoined, v)
 
         if not module.check_mode:
             # Remove key if the new value is none