diff --git a/babi/prompt.py b/babi/prompt.py
index 6e15a84..13a128f 100644
--- a/babi/prompt.py
+++ b/babi/prompt.py
@@ -110,7 +110,7 @@ def _tab(self) -> None:
 
     def _complete_file(self) -> None:
         # only allow completion at the end of the prompt or before a separator
-        if self._x != len(self._s) and self._s[self._x] not in ("/", " "):
+        if self._x != len(self._s) and self._s[self._x] not in ('/', ' '):
             return
         partial = self._s[:self._x]
         completions = glob.glob(f'{partial}*')