diff --git a/Lib/sre.py b/Lib/sre.py
index 455cd27..637b776 100644
--- a/Lib/sre.py
+++ b/Lib/sre.py
@@ -90,7 +90,7 @@
 def _subn(pattern, template, string, count=0):
     # internal: pattern.subn implementation hook
     if callable(template):
-        filter = callable
+        filter = template
     else:
         # FIXME: prepare template
         def filter(match, template=template):