diff --git a/Data/HashMap/Array.hs b/Data/HashMap/Array.hs
index ca64da08..2e714740 100644
--- a/Data/HashMap/Array.hs
+++ b/Data/HashMap/Array.hs
@@ -5,8 +5,8 @@
 --
 -- Note that no bounds checking are performed.
 module Data.HashMap.Array
-    ( Array
-    , MArray
+    ( Array (..)
+    , MArray (..)
 
       -- * Creation
     , new
diff --git a/Data/HashMap/Internal.hs b/Data/HashMap/Internal.hs
new file mode 100644
index 00000000..00d26419
--- /dev/null
+++ b/Data/HashMap/Internal.hs
@@ -0,0 +1,8 @@
+module Data.HashMap.Internal
+    ( Array (..)
+    , Leaf (..)
+    , HashMap (..)
+    ) where
+
+import Data.HashMap.Array
+import Data.HashMap.Base
diff --git a/unordered-containers.cabal b/unordered-containers.cabal
index 72a9dd4c..43438782 100644
--- a/unordered-containers.cabal
+++ b/unordered-containers.cabal
@@ -30,6 +30,7 @@ library
     Data.HashMap.Lazy
     Data.HashMap.Strict
     Data.HashSet
+    Data.HashMap.Internal
   other-modules:
     Data.HashMap.Array
     Data.HashMap.Base