diff --git a/clash-lib.cabal b/clash-lib.cabal
--- a/clash-lib.cabal
+++ b/clash-lib.cabal
@@ -1,5 +1,5 @@
 Name:                 clash-lib
-Version:              0.3.0.1
+Version:              0.3.0.2
 Synopsis:             CAES Language for Synchronous Hardware - As a Library
 Description:
   CλaSH (pronounced ‘clash’) is a functional hardware description language that
@@ -25,7 +25,7 @@
   .
   * <https://github.com/christiaanb/Idris-dev Idris Frontend>
   .
-  * <https://github.com/christiaanb/clash2 GHC/Haskell Frontend>
+  * <http://hackage.haskell.org/package/clash-ghc GHC/Haskell Frontend>
   .
   .
   Prelude library: <http://hackage.haskell.org/package/clash-prelude>
diff --git a/src/CLaSH/Netlist/BlackBox.hs b/src/CLaSH/Netlist/BlackBox.hs
--- a/src/CLaSH/Netlist/BlackBox.hs
+++ b/src/CLaSH/Netlist/BlackBox.hs
@@ -56,7 +56,7 @@
     (funInps,declssF)     <- fmap (unzip . catMaybes) $ mapM (runMaybeT . mkFunInput resId . fst) funArgs
 
     -- Make context result
-    let res = case synchronizedClk (unembed $ V.varType resId) of
+    let res = case synchronizedClk tcm (unembed $ V.varType resId) of
                 Just clk -> Right . (,clk) . mkBasicId . pack $ name2String (V.varName resId)
                 Nothing  -> Left . mkBasicId . pack $ name2String (V.varName resId)
     resTy <- N.unsafeCoreTypeToHWTypeM $(curLoc) (unembed $ V.varType resId)
@@ -90,8 +90,9 @@
 
 mkInput (Var ty v, False) = do
   let vT = mkBasicId . pack $ name2String v
+  tcm  <- Lens.use tcCache
   hwTy <- lift $ N.unsafeCoreTypeToHWTypeM $(curLoc) ty
-  case synchronizedClk ty of
+  case synchronizedClk tcm ty of
     Just clk -> return ((Right (vT,clk), hwTy),[])
     Nothing  -> return ((Left vT, hwTy),[])
 
diff --git a/src/CLaSH/Netlist/Util.hs b/src/CLaSH/Netlist/Util.hs
--- a/src/CLaSH/Netlist/Util.hs
+++ b/src/CLaSH/Netlist/Util.hs
@@ -73,14 +73,15 @@
 coreTypeToHWTypeM ty = hush <$> (coreTypeToHWType <$> Lens.use typeTranslator <*> Lens.use tcCache <*> pure ty)
 
 -- | Returns the name and period of the clock corresponding to a type
-synchronizedClk :: Type
+synchronizedClk :: HashMap TyConName TyCon -- ^ TyCon cache
+                -> Type
                 -> Maybe (Identifier,Int)
-synchronizedClk ty
+synchronizedClk tcm ty
   | not . null . typeFreeVars $ ty = Nothing
   | Just (tyCon,args) <- splitTyConAppM ty
   = case name2String tyCon of
       "CLaSH.Signal.Types.Signal"     -> Just (pack "clk1000",1000)
-      "CLaSH.Sized.Vector.Vec"        -> synchronizedClk (args!!1)
+      "CLaSH.Sized.Vector.Vec"        -> synchronizedClk tcm (args!!1)
       "CLaSH.Signal.Implicit.SignalP" -> Just (pack "clk1000",1000)
       "CLaSH.Signal.Types.CSignal"    -> case (head args) of
                                            (LitTy (NumTy i)) -> Just (pack ("clk" ++ show i),i)
@@ -88,7 +89,15 @@
       "CLaSH.Signal.Types.CSignalP"   -> case (head args) of
                                            (LitTy (NumTy i)) -> Just (pack ("clk" ++ show i),i)
                                            _ -> error $ $(curLoc) ++ "Clock period not a simple literal: " ++ showDoc ty
-      _                               -> Nothing
+      _                               -> case tyConDataCons (tcm HashMap.! tyCon) of
+                                           [dc] -> let argTys   = dcArgTys dc
+                                                       argTVs   = dcUnivTyVars dc
+                                                       argSubts = zip argTVs args
+                                                       args'    = map (substTys argSubts) argTys
+                                                   in case args' of
+                                                      (arg:_) -> synchronizedClk tcm arg
+                                                      _ -> Nothing
+                                           _    -> Nothing
   | otherwise
   = Nothing