diff --git a/happstack-ixset.cabal b/happstack-ixset.cabal
--- a/happstack-ixset.cabal
+++ b/happstack-ixset.cabal
@@ -1,5 +1,5 @@
 Name:                happstack-ixset
-Version:             0.3.2
+Version:             0.4.1
 Synopsis:            Efficient relational queries on Haskell sets. 
 Description:         Just pick which parts of your data structures you want indexed using an easy to use template-haskell function. Spare yourself the need to write, run, and maintain code that marshalls your data to/from an external relational database just for efficient queries. happstack-ixset relies on generics and TH to spare you the boilerplate normally required for such tasks. 
 License:             BSD3
@@ -14,7 +14,7 @@
 source-repository head
     type:     darcs
     subdir:   happstack-ixset
-    location: http://patch-tag.com/publicrepos/happstack
+    location: http://patch-tag.com/r/mae/happstack/pullrepo
 
 flag base4
 
@@ -28,9 +28,15 @@
   else
     Build-Depends:     base < 4
 
+  if impl(ghc >= 6.12.1)
+    Build-Depends:    syb-with-class >= 0.6.1
+  else
+    Build-Depends:    syb-with-class < 0.6.1
+
+
   Build-Depends:       containers,
-                       happstack-data >= 0.3.2 && < 0.4,
-                       happstack-util >= 0.3.2 && < 0.4,
+                       happstack-data >= 0.4.1 && < 0.5,
+                       happstack-util >= 0.4.1 && < 0.5,
                        mtl,
                        syb-with-class,
                        template-haskell
diff --git a/src/Happstack/Data/IxSet.hs b/src/Happstack/Data/IxSet.hs
--- a/src/Happstack/Data/IxSet.hs
+++ b/src/Happstack/Data/IxSet.hs
@@ -168,16 +168,26 @@
    @$(inferIxSet "FooDB" ''Foo 'noCalcs [''Int,''String])@ will 
    build a type synonym @type FooDB = IxSet Foo@ with @Int@ and
    @String@ as indexes.
+
+   WARNING: The type specified as the first index must be a type which
+   appears in all values in the 'IxSet' or 'toList' and 'toSet' will
+   not function properly. You can always use the element type
+   itself. For example,    
+   @$(inferIxSet "FooDB" ''Foo 'noCalcs [''Foo, ''Int,''String])@
+
 -} 
 inferIxSet :: String -> TH.Name -> TH.Name -> [TH.Name] -> Q [Dec]
 inferIxSet ixset typeName calName entryPoints
     = do calInfo <- reify calName
          typeInfo <- reify typeName
-         let (context,names) = case typeInfo of
+         let (context,binders) = case typeInfo of
                                  TyConI (DataD ctxt _ nms _ _) -> (ctxt,nms)
                                  TyConI (NewtypeD ctxt _ nms _ _) -> (ctxt,nms)
                                  TyConI (TySynD _ nms _) -> ([],nms)
                                  _ -> error "unexpected match"
+
+             names = map tyVarBndrToName binders
+
              typeCon = foldl appT (conT typeName) (map varT names)
          case calInfo of
            VarI _ t _ _ ->
@@ -185,7 +195,7 @@
                    getCalType (ForallT _names _ t') = getCalType t'
                    getCalType (AppT (AppT ArrowT _) t') = t'
                    getCalType t' = error ("Unexpected type: " ++ pprint t')
-                   mkEntryPoint n = appE (conE 'Ix) (sigE (varE 'Map.empty) (forallT names (return context) $
+                   mkEntryPoint n = appE (conE 'Ix) (sigE (varE 'Map.empty) (forallT binders (return context) $
                                                                              appT (appT (conT ''Map) (conT n)) (appT (conT ''Set) typeCon)))
                in do i <- instanceD' (return context) (appT (appT (conT ''Indexable) typeCon) (return calType))
                           [d| empty :: IxSet a
@@ -193,9 +203,18 @@
                               calcs :: a -> b
                               calcs = $(varE calName) |]
                      let ixType = appT (conT ''IxSet) typeCon
-                     ixType' <- tySynD (mkName ixset) names ixType
+                     ixType' <- tySynD (mkName ixset) binders ixType
                      return $ [i, ixType']  -- ++ d
            _ -> error "unexpected match"
+
+#if MIN_VERSION_template_haskell(2,4,0)
+tyVarBndrToName (PlainTV nm) = nm
+tyVarBndrToName (KindedTV nm _) = nm
+#else
+tyVarBndrToName = id
+#endif
+
+
 
 -- modification operations