diff --git a/babel/messages/frontend.py b/babel/messages/frontend.py
index aeda9763b..65ff661a0 100644
--- a/babel/messages/frontend.py
+++ b/babel/messages/frontend.py
@@ -458,7 +458,7 @@ def finalize_options(self):
 
         ignore_dirs = listify_value(self.ignore_dirs)
         if ignore_dirs:
-            self.directory_filter = _make_directory_filter(self.ignore_dirs)
+            self.directory_filter = _make_directory_filter(ignore_dirs)
         else:
             self.directory_filter = None