diff --git a/mercurial/filemerge.py b/mercurial/filemerge.py
index 5388a96f95..bdd9a3ec3d 100644
--- a/mercurial/filemerge.py
+++ b/mercurial/filemerge.py
@@ -75,6 +75,7 @@ def _picktool(repo, ui, path, binary, symlink):
             return True
         return False
 
+    # internal config: ui.forcemerge
     # forcemerge comes from command line arguments, highest priority
     force = ui.config('ui', 'forcemerge')
     if force: