diff --git a/kitty/window.py b/kitty/window.py
index 1d22cf073..7618bf191 100644
--- a/kitty/window.py
+++ b/kitty/window.py
@@ -488,7 +488,7 @@ def set_extra(self, extra: str) -> None:
 
 def replace_control_codes(text: str) -> str:
     # Replace all control codes other than tab, newline and space with their graphical counterparts
-    def sub(m: re.Match[str]) -> str:
+    def sub(m: 're.Match[str]') -> str:
         c = ord(m.group())
         if c < 0x20:
             return chr(0x2400 + c)