diff --git a/Web/Routes/TH.hs b/Web/Routes/TH.hs
--- a/Web/Routes/TH.hs
+++ b/Web/Routes/TH.hs
@@ -47,18 +47,13 @@
     = do c <- parseInfo name
          case c of
            Tagged cons cx keys ->
-               do let context = [ mkCtx ''PathInfo [varT key] | key <- keys ] ++ map return cx
-                  i <- instanceD (sequence context) (mkType ''PathInfo [mkType name (map varT keys)])
+               do let context = pure $  [ AppT (ConT ''PathInfo) (VarT key) | key <- keys ] ++ cx
+                  i <- instanceD context (mkType ''PathInfo [mkType name (map varT keys)])
                        [ toPathSegmentsFn cons
                        , fromPathSegmentsFn cons
                        ]
                   return [i]
     where
-#if MIN_VERSION_template_haskell(2,4,0)
-      mkCtx = classP
-#else
-      mkCtx = mkType
-#endif
       toPathSegmentsFn :: [(Name, Int)] -> DecQ
       toPathSegmentsFn cons
           = do inp <- newName "inp"
@@ -92,23 +87,18 @@
 parseInfo name
     = do info <- reify name
          case info of
-#if MIN_VERSION_template_haskell(2,11,0)
            TyConI (DataD cx _ keys _ cs _)    -> return $ Tagged (map conInfo cs) cx $ map conv keys
            TyConI (NewtypeD cx _ keys _ con _)-> return $ Tagged [conInfo con] cx $ map conv keys
-#else
-           TyConI (DataD cx _ keys cs _)    -> return $ Tagged (map conInfo cs) cx $ map conv keys
-           TyConI (NewtypeD cx _ keys con _)-> return $ Tagged [conInfo con] cx $ map conv keys
-#endif
-           _                                ->  error $ "derivePathInfo - invalid input: " ++ pprint info
     where conInfo (NormalC n args) = (n, length args)
           conInfo (RecC n args) = (n, length args)
           conInfo (InfixC _ n _) = (n, 2)
           conInfo (ForallC _ _ con) = conInfo con
-#if MIN_VERSION_template_haskell(2,4,0)
+#if MIN_VERSION_template_haskell(2,17,0)
+          conv (PlainTV nm _) = nm
+          conv (KindedTV nm _ _) = nm
+#else
           conv (PlainTV nm) = nm
           conv (KindedTV nm _) = nm
-#else
-          conv = id
 #endif
 
 -- | the standard formatter
@@ -143,11 +133,7 @@
 parseMethods con =
     do info <- reify con
        case info of
-#if MIN_VERSION_template_haskell(2,11,0)
          (DataConI _ ty _) ->
-#else
-         (DataConI _ ty _ _) ->
-#endif
              do runIO $ print ty
                 runIO $ print $ lastTerm ty
                 return $ extractMethods (lastTerm ty)
diff --git a/test/Test.hs b/test/Test.hs
--- a/test/Test.hs
+++ b/test/Test.hs
@@ -1,4 +1,4 @@
-{-# LANGUAGE GeneralizedNewtypeDeriving, OverloadedStrings, TemplateHaskell #-}
+{-# LANGUAGE ExtendedDefaultRules, FlexibleInstances, GeneralizedNewtypeDeriving, OverloadedStrings, TemplateHaskell, DatatypeContexts #-}
 
 module Main (main) where
 
@@ -11,29 +11,30 @@
 
 newtype ArticleId = ArticleId Int deriving (Eq, Show, Num, PathInfo, Arbitrary)
 
-data Sitemap
-    = Home
+-- the use of Show is and 'a' is to exercise the context generation of the 'derivePathInfo' code
+data (Show a) => Sitemap a
+    = Home a
     | Article ArticleId
     deriving (Eq, Show)
 
 derivePathInfo ''Sitemap
 
-instance Arbitrary Sitemap where
-    arbitrary = oneof [return Home, fmap Article arbitrary]
+instance Arbitrary (Sitemap Int) where
+    arbitrary = oneof [fmap Home arbitrary, fmap Article arbitrary]
 
-prop_PathInfo_isomorphism :: Sitemap -> Bool
+prop_PathInfo_isomorphism :: Sitemap Int -> Bool
 prop_PathInfo_isomorphism = pathInfoInverse_prop
 
 case_toPathInfo :: Assertion
 case_toPathInfo =
-    do toPathInfo Home @?= "/home"
-       toPathInfo (Article 0) @?= "/article/0"
+    do toPathInfo ((Home 1) :: Sitemap Int) @?= "/home/1"
+       toPathInfo ((Article 0):: Sitemap Int) @?= "/article/0"
 
 case_fromPathInfo :: Assertion
 case_fromPathInfo =
-    do fromPathInfo "/home" @?= Right Home
+    do fromPathInfo "/home/1"      @?= ((Right (Home (1 :: Int))) :: Either String (Sitemap Int))
        fromPathInfo "/article/0" @?= Right (Article 0)
-       case fromPathInfo "/" :: Either String Sitemap of
+       case fromPathInfo "/" :: Either String (Sitemap Int) of
          Left _ -> return ()
          url    -> assertFailure $ "expected a Left, but got: " ++ show url
 
diff --git a/web-routes-th.cabal b/web-routes-th.cabal
--- a/web-routes-th.cabal
+++ b/web-routes-th.cabal
@@ -1,5 +1,5 @@
 Name:             web-routes-th
-Version:          0.22.6.6
+Version:          0.22.7
 License:          BSD3
 License-File:     LICENSE
 Author:           jeremy@seereason.com
@@ -12,7 +12,7 @@
                   Template Haskell.
 Cabal-Version:    >= 1.10
 Build-type:       Simple
-tested-with:      GHC == 7.6.3, GHC == 7.8.4, GHC == 7.10.3, GHC == 8.0.1, GHC == 8.2.2, GHC == 8.4.1, GHC == 8.6.3, GHC == 8.8.3, GHC == 8.10.1
+tested-with:      GHC==8.0.2, GHC==8.2.2, GHC==8.4.1, GHC==8.6.5, GHC==8.8.4, GHC==8.10.7, GHC==9.0.2, GHC==9.2.2
 
 source-repository head
     type:     git
@@ -23,21 +23,21 @@
   type             : exitcode-stdio-1.0
   main-is          : Test.hs
   hs-source-dirs   : test
-  build-depends    : base == 4.*,
-                     hspec >= 2.2 && < 2.8,
+  build-depends    : base  >= 4.9 && < 5,
+                     hspec >= 2.2 && < 2.10,
                      HUnit,
                      QuickCheck,
-                     web-routes,
+                     web-routes >= 0.27 && < 0.28,
                      web-routes-th
 
 Library
         Default-Language: Haskell2010
-        Build-Depends:    base >= 4 && < 5,
-                          parsec >= 2 && < 4,
-                          template-haskell < 2.17,
-                          text,
-                          split,
-                          web-routes >= 0.26
+        Build-Depends:    base       >= 4.9 && < 5,
+                          parsec     >= 2 && < 4,
+                          template-haskell >= 2.11 && < 2.19,
+                          text       >= 0.11 && < 2.1,
+                          split      >= 0.2  && < 0.3,
+                          web-routes >= 0.26 && < 0.28
         Exposed-Modules:  Web.Routes.TH
 
 source-repository head