diff --git a/namespace.cabal b/namespace.cabal
--- a/namespace.cabal
+++ b/namespace.cabal
@@ -1,5 +1,5 @@
 name:                namespace
-version:             0.1.2.1
+version:             0.1.2.2
 synopsis:            A Generic Haskell library for managing namespaces
 description:         Please see README.md
 homepage:            https://github.com/xu-hao/namespace
diff --git a/src/Data/Namespace/Namespace.hs b/src/Data/Namespace/Namespace.hs
--- a/src/Data/Namespace/Namespace.hs
+++ b/src/Data/Namespace/Namespace.hs
@@ -46,7 +46,7 @@
 concatKey key = mapKeys (act (NamespacePath [key]))
 
 pathKey :: Key k => Map k a -> Map (ObjectPath k) a
-pathKey = mapKeys (\ObjectPath (NamespacePath []) key) o m ) mempty
+pathKey = mapKeys (ObjectPath (NamespacePath []))
 
 allObjects :: Key k => Namespace k a -> Map (ObjectPath k) a
 allObjects ns = pathKey (topLevelObjects ns) <> mconcat (elems (mapWithKey (\key ns2 -> concatKey key (allObjects ns2)) (topLevelNamespaces ns)))