diff --git a/IPython/terminal/interactiveshell.py b/IPython/terminal/interactiveshell.py
index bcbc668..1792523 100644
--- a/IPython/terminal/interactiveshell.py
+++ b/IPython/terminal/interactiveshell.py
@@ -203,7 +203,6 @@ class TerminalInteractiveShell(InteractiveShell):
 
     @observe("editing_mode")
     def _editing_mode_changed(self, change):
-        u_mode = change.new.upper()
         if self.pt_app:
             self.init_prompt_toolkit_cli()