diff --git a/fb-persistent.cabal b/fb-persistent.cabal
--- a/fb-persistent.cabal
+++ b/fb-persistent.cabal
@@ -1,5 +1,5 @@
 name:              fb-persistent
-version:           0.1.1
+version:           0.1.2
 license:           BSD3
 license-file:      LICENSE
 author:            Felipe Lessa
diff --git a/src/Facebook/Persistent.hs b/src/Facebook/Persistent.hs
--- a/src/Facebook/Persistent.hs
+++ b/src/Facebook/Persistent.hs
@@ -12,6 +12,7 @@
 -- @
 module Facebook.Persistent () where
 
+import Control.Applicative ((<$>))
 import Database.Persist
 import Facebook
 
@@ -25,4 +26,12 @@
                            \Could not parse action"
           Left err -> Left err
     sqlType = sqlType . show
+    isNullable _ = False
+
+
+-- | From @fb-persistent@.  Since 0.1.2.
+instance PersistField Id where
+    toPersistValue = toPersistValue . idCode
+    fromPersistValue v = Id <$> fromPersistValue v
+    sqlType = sqlType . idCode
     isNullable _ = False