diff --git a/gtm b/gtm
index 89dab67..1ccda4c 100755
--- a/gtm
+++ b/gtm
@@ -1447,7 +1447,7 @@ def handle_keyboard_input(key, state: AppState) -> AppState:
 
 # --- Main Application ---
 
-def main(stdscr, filename, show_add, show_del, mouse, show_diff=True, wrap_lines=True, show_line_numbers=True):
+def main(stdscr, filename, show_add, show_del, mouse=True, show_diff=True, wrap_lines=True, show_line_numbers=True):
     try:
         curses.curs_set(0)
     except: