diff --git a/CouchDB.cabal b/CouchDB.cabal
--- a/CouchDB.cabal
+++ b/CouchDB.cabal
@@ -1,5 +1,5 @@
 Name:           CouchDB
-Version:        0.8.1.0
+Version:        0.8.1.1
 Cabal-Version:	>= 1.2.4
 Copyright:      Copyright (c) 2008 Arjun Guha and Brendan Hickey
 License:        BSD3
@@ -19,7 +19,7 @@
   Hs-Source-Dirs:
     src
   Build-Depends:
-    base, mtl, containers, network, HTTP>=3001.1.4, json>=0.3.3
+    base, mtl, containers, network, HTTP<4000.0.0, json>=0.3.3
   ghc-options:
     -fwarn-incomplete-patterns
   Extensions:     
diff --git a/src/Database/CouchDB.hs b/src/Database/CouchDB.hs
--- a/src/Database/CouchDB.hs
+++ b/src/Database/CouchDB.hs
@@ -205,7 +205,7 @@
 getAndUpdateDoc :: (JSON a)
                 => DB -- ^database
                 -> Doc -- ^document name
-                -> (a -> a) -- ^update function
+                -> (a -> IO a) -- ^update function
                 -> CouchMonad (Maybe Rev) -- ^If the update succeeds,
                                           -- return the revision number
                                           -- of the result.
diff --git a/src/Database/CouchDB/Unsafe.hs b/src/Database/CouchDB/Unsafe.hs
--- a/src/Database/CouchDB/Unsafe.hs
+++ b/src/Database/CouchDB/Unsafe.hs
@@ -179,7 +179,7 @@
 getAndUpdateDoc :: (JSON a)
                 => String -- ^database
                 -> String -- ^document name
-                -> (a -> a) -- ^update function
+                -> (a -> IO a) -- ^update function
                 -> CouchMonad (Maybe String) -- ^If the update succeeds,
                                              -- return the revision number
                                              -- of the result.
@@ -187,7 +187,8 @@
   r <- getDoc db docId
   case r of
     Just (id,rev,val) -> do
-      r <- updateDoc db (id,rev) (fn val)
+      val' <- liftIO (fn val)
+      r <- updateDoc db (id,rev) val'
       case r of
         Just (id,rev) -> return (Just $ fromJSString rev)
         Nothing -> return Nothing