diff --git a/bot.py b/bot.py
index 58cb723..4ed32b2 100644
--- a/bot.py
+++ b/bot.py
@@ -298,9 +298,8 @@ def cmd_uptime(match: Match[str]) -> Response:
 @handle_message(r'!pep[ ]?(?P<pep_num>\d{1,4})')
 def cmd_pep(match: Match[str]) -> Response:
     *_, number = match.groups()
-    return MessageResponse(
-        match, f'https://www.python.org/dev/peps/pep-{int(number).zfill(4)}/',
-    )
+    n = str(int(number)).zfill(4)
+    return MessageResponse(match, f'https://www.python.org/dev/peps/pep-{n}/')
 
 
 COMMAND_RE = re.compile(r'!\w+')