diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,9 @@
 # Changelog
 
+#### 0.2.10.5
+
+* Use new version of `rest-core`.
+
 #### 0.2.10.4
 
 * Allow `happstack-server == 7.4.*`
diff --git a/rest-happstack.cabal b/rest-happstack.cabal
--- a/rest-happstack.cabal
+++ b/rest-happstack.cabal
@@ -1,5 +1,5 @@
 name:                rest-happstack
-version:             0.2.10.4
+version:             0.2.10.5
 description:         Rest driver for Happstack.
 synopsis:            Rest driver for Happstack.
 maintainer:          code@silk.co
@@ -28,6 +28,6 @@
     , containers >= 0.4 && < 0.6
     , happstack-server >= 7.0.5 && < 7.5
     , mtl >= 2.0 && < 2.3
-    , rest-core >= 0.31 && < 0.34
+    , rest-core == 0.34.*
     , rest-gen >= 0.14 && < 0.17
     , utf8-string == 0.3.*
diff --git a/src/Rest/Driver/Happstack.hs b/src/Rest/Driver/Happstack.hs
--- a/src/Rest/Driver/Happstack.hs
+++ b/src/Rest/Driver/Happstack.hs
@@ -38,9 +38,9 @@
   setHeader       = Happstack.setHeaderM
   setResponseCode = Happstack.setResponseCode
 
-toRestMethod :: Happstack.Method -> Rest.Method
-toRestMethod Happstack.GET    = Rest.GET
-toRestMethod Happstack.POST   = Rest.POST
-toRestMethod Happstack.PUT    = Rest.PUT
-toRestMethod Happstack.DELETE = Rest.DELETE
-toRestMethod mthd             = Rest.Unknown (show mthd)
+toRestMethod :: Happstack.Method -> Maybe Rest.Method
+toRestMethod Happstack.GET    = Just Rest.GET
+toRestMethod Happstack.POST   = Just Rest.POST
+toRestMethod Happstack.PUT    = Just Rest.PUT
+toRestMethod Happstack.DELETE = Just Rest.DELETE
+toRestMethod _                = Nothing