diff --git a/.gitmodules b/.gitmodules
index 91468aac..5f97538c 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -1,3 +1,6 @@
 [submodule "scripts"]
 	path = scripts
 	url = git://github.com/yesodweb/scripts.git
+[submodule "authenticate"]
+	path = authenticate
+	url = https://github.com/yesodweb/authenticate.git
diff --git a/authenticate b/authenticate
new file mode 160000
index 00000000..262d06e0
--- /dev/null
+++ b/authenticate
@@ -0,0 +1 @@
+Subproject commit 262d06e045b658e83abfc7a34c5f9878254c7046
diff --git a/yesod-auth/Yesod/Auth/HashDB.hs b/yesod-auth/Yesod/Auth/HashDB.hs
index 6c8c9a60..a8071b45 100644
--- a/yesod-auth/Yesod/Auth/HashDB.hs
+++ b/yesod-auth/Yesod/Auth/HashDB.hs
@@ -59,6 +59,7 @@
 -------------------------------------------------------------------------------
 module Yesod.Auth.HashDB
     ( HashDBUser(..)
+    , Unique (..)
     , setPassword
       -- * Authentification
     , validateUser