diff --git a/src/calibre/gui2/metadata/single.py b/src/calibre/gui2/metadata/single.py
index 6089b5422b..54067f4c0f 100644
--- a/src/calibre/gui2/metadata/single.py
+++ b/src/calibre/gui2/metadata/single.py
@@ -321,7 +321,7 @@ class MetadataSingleDialogBase(ResizableDialog):
                         _('Could not open %s. Is it being used by another'
                         ' program?')%fname, det_msg=traceback.format_exc(),
                         show=True)
-                return False
+                return
         if mi is None:
             return
         cdata = None