diff --git a/tests/failfilemerge.py b/tests/failfilemerge.py
--- a/tests/failfilemerge.py
+++ b/tests/failfilemerge.py
@@ -9,11 +9,8 @@
 )
 
 
-def failfilemerge(
-    filemergefn, premerge, repo, wctx, mynode, orig, fcd, fco, fca, labels=None
-):
+def failfilemerge(*args, **kwargs):
     raise error.Abort(b"^C")
-    return filemergefn(premerge, repo, mynode, orig, fcd, fco, fca, labels)
 
 
 def extsetup(ui):