diff --git a/src/narrowmerge.py b/src/narrowmerge.py
--- a/src/narrowmerge.py
+++ b/src/narrowmerge.py
@@ -15,12 +15,10 @@
 )
 
 def setup():
-    def _manifestmerge(orig, repo, wctx, p2, pa, branchmerge, force, partial,
-                      acceptremote, followcopies):
+    def _manifestmerge(orig, repo, wctx, p2, pa, branchmerge, *args, **kwargs):
         """Filter updates to only lay out files that match the narrow spec."""
         actions, diverge, renamedelete = orig(
-            repo, wctx, p2, pa, branchmerge, force, partial,
-            acceptremote, followcopies)
+            repo, wctx, p2, pa, branchmerge, *args, **kwargs)
 
         if not util.safehasattr(repo, 'narrowmatch'):
             return actions, diverge, renamedelete