diff --git a/aider/coders/base_coder.py b/aider/coders/base_coder.py
index 1818bca01..b00992c8f 100755
--- a/aider/coders/base_coder.py
+++ b/aider/coders/base_coder.py
@@ -1598,7 +1598,7 @@ class Coder:
         group = ConfirmGroup(new_mentions)
         for rel_fname in sorted(new_mentions):
             if self.io.confirm_ask(
-                f"Add file to the chat?", subject=rel_fname, group=group, allow_never=True
+                "Add file to the chat?", subject=rel_fname, group=group, allow_never=True
             ):
                 self.add_rel_fname(rel_fname)
                 added_fnames.append(rel_fname)