diff --git a/scripts/process-text-files.py b/scripts/process-text-files.py
index da3f748..ee60c4b 100644
--- a/scripts/process-text-files.py
+++ b/scripts/process-text-files.py
@@ -381,7 +381,7 @@ class Cmd(jwutils.Cmd):
         if regex is not None:
             for entry in _scantree(args.root, args.maxdepth):
                 if re.search(regex, entry.name):
-                    root = os.dirname(entry.path)
+                    root = os.path.dirname(entry.path)
                     if not root:
                         root = '.'
                     files.append((root, entry.path))