diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,6 @@
+# 0.5.1
+* Allow for newer dependencies.
+
 # 0.5
 
 * Upgrade to persistent 2
diff --git a/snaplet-persistent.cabal b/snaplet-persistent.cabal
--- a/snaplet-persistent.cabal
+++ b/snaplet-persistent.cabal
@@ -1,5 +1,5 @@
 name:           snaplet-persistent
-version:        0.5
+version:        0.5.1
 synopsis:       persistent snaplet for the Snap Framework
 description:    Snaplet support for using the Postgresql database
                 with a Snap Framework application via the persistent
@@ -25,6 +25,10 @@
   type:     git
   location: https://github.com/soostone/snaplet-persistent.git
 
+flag lib-Werror
+  default: False
+  manual: True
+
 Library
   hs-source-dirs: src
 
@@ -41,25 +45,28 @@
     bytestring                 >= 0.9.1   && < 0.11,
     clientsession              >= 0.7.2   && < 0.10,
     configurator               >= 0.2     && < 0.4,
-    heist                      >= 0.14    && < 0.15,
-    lens                       >= 3.7.6   && < 4.7,
-    errors                     >= 1.4     && < 1.5,
-    MonadCatchIO-transformers  >= 0.3     && < 0.4,
+    heist                      >= 0.14    && < 1.1,
+    lens                       >= 3.7.6   && < 5,
+    errors                     >= 1.4     && < 2.3,
     monad-logger               >= 0.2.4   && < 0.4,
     mtl                        >= 2       && < 3,
-    persistent                 >= 2.0     && < 2.2,
-    persistent-postgresql      >= 2.0     && < 2.2,
-    persistent-template        >= 2.0     && < 2.2,
+    persistent                 >= 2.0     && < 2.8,
+    persistent-postgresql      >= 2.0     && < 2.7,
+    persistent-template        >= 2.0     && < 2.6,
     readable                   >= 0.1     && < 0.4,
     resource-pool              >= 0.2     && < 0.3,
     resourcet                  >= 0.4     && < 1.2,
     safe                       >= 0.3     && < 0.4,
-    snap                       >= 0.13    && < 0.14,
+    snap                       >= 0.13    && < 1.1,
     text                       >= 0.11    && < 1.3,
-    time                       >= 1.1     && < 1.6,
-    transformers               >= 0.2     && < 0.5,
-    unordered-containers       >= 0.2     && < 0.3
+    time                       >= 1.1     && < 1.7,
+    transformers               >= 0.2     && < 0.6,
+    unordered-containers       >= 0.2     && < 0.3,
+    map-syntax
 
 
   ghc-options: -Wall -fwarn-tabs -funbox-strict-fields
                -fno-warn-orphans -fno-warn-unused-do-bind
+
+  if flag(lib-Werror)
+    ghc-options: -Werror
diff --git a/src/Snap/Snaplet/Auth/Backends/Persistent.hs b/src/Snap/Snaplet/Auth/Backends/Persistent.hs
--- a/src/Snap/Snaplet/Auth/Backends/Persistent.hs
+++ b/src/Snap/Snaplet/Auth/Backends/Persistent.hs
@@ -30,6 +30,7 @@
 import           Control.Monad
 import           Control.Monad.Trans
 import qualified Data.HashMap.Strict                         as HM
+import qualified Data.Map.Syntax                             as MS
 import           Data.Maybe
 import           Data.Text                                   (Text)
 import qualified Data.Text                                   as T
@@ -107,7 +108,7 @@
 -- 'AuthUser'.
 dbUserSplices :: Monad n
               => Splices (RuntimeSplice n (Entity SnapAuthUser) -> Splice n)
-dbUserSplices = mapV (deferMap (return . db2au)) userCSplices
+dbUserSplices = MS.mapV (deferMap (return . db2au)) userCSplices
 
 
 data PersistAuthManager = PAM {
@@ -156,6 +157,7 @@
                  , activeUser = Nothing
                  , minPasswdLen = asMinPasswdLen aus
                  , rememberCookieName = asRememberCookieName aus
+                 , rememberCookieDomain = Nothing
                  , rememberPeriod = asRememberPeriod aus
                  , siteKey = key
                  , lockout = asLockout aus
@@ -171,7 +173,7 @@
 -- | Get the db key from an 'AuthUser'
 userDBKey :: AuthUser -> Maybe SnapAuthUserId
 userDBKey au = case userId au of
-                 Nothing -> Nothing
+                 Nothing         -> Nothing
                  Just (UserId k) -> Just . mkKey $ (readT k :: Int)