diff --git a/mercurial/merge.py b/mercurial/merge.py
--- a/mercurial/merge.py
+++ b/mercurial/merge.py
@@ -1058,7 +1058,7 @@ def update(repo, node, branchmerge, forc
 
         ### check phase
         if not overwrite and len(pl) > 1:
-            raise util.Abort(_("outstanding uncommitted merges"))
+            raise util.Abort(_("outstanding uncommitted merge"))
         if branchmerge:
             if pas == [p2]:
                 raise util.Abort(_("merging with a working directory ancestor"
diff --git a/tests/test-largefiles.t b/tests/test-largefiles.t
--- a/tests/test-largefiles.t
+++ b/tests/test-largefiles.t
@@ -1705,7 +1705,7 @@ Test status after merging with a branch 
 - make sure update of merge with removed largefiles fails as expected
   $ hg rm sub2/large6
   $ hg up -r.
-  abort: outstanding uncommitted merges
+  abort: outstanding uncommitted merge
   [255]
 
 - revert should be able to revert files introduced in a pending merge