diff --git a/ECTA/Plugin.hs b/ECTA/Plugin.hs
--- a/ECTA/Plugin.hs
+++ b/ECTA/Plugin.hs
@@ -148,6 +148,7 @@
       let (scopeNode, anyArg, argNodes, skels, groups) =
             let argNodes = ngnodes local_scope_comps
                 addSyms st tt = map (Bi.bimap (Symbol . st) (tt . typeToFta))
+                                . filter (\(_,t) -> isSafe t)
                 gnodes = addSyms id (generalize global_scope_comps)
                 ngnodes = addSyms id id
                 anyArg = Node $ map (\(s,t) -> Edge s [t]) $ 
@@ -157,7 +158,8 @@
                 groups = Map.fromList $ map (\(t,_) -> (t,[t])) scope_comps
             in (scopeNode, anyArg, argNodes, skels, groups)
       case typeToSkeleton ty of
-         Just (t, cons) | resNode <- typeToFta t -> do
+         Just (t, cons) | isSafe t,
+                          resNode <- typeToFta t -> do
              let res = getAllTerms $ refold $ reduceFully $ filterType scopeNode resNode
              -- We ignore ppterms for now, because they need to be printed differently.
              -- ppterms <- concatMapM (prettyMatch skels groups . prettyTerm ) res
@@ -172,13 +174,10 @@
                          f _ = Nothing
                  filtered_fits = map (RawHoleFit . text . unpack . parIfReq) $
                                  filter (not . flip Set.member fit_set) ecta_fits
-                         
-                 
-
-                 
              return $ found_fits ++ filtered_fits
-         _ ->  do liftIO $ putStrLn $  "Could not skeleton `" ++ showSDocUnsafe (ppr ty) ++"`"
-                  return []
+         _ ->  return found_fits
+         -- liftIO $ putStrLn $  "Could not skeleton `" ++ showSDocUnsafe (ppr ty) ++"`"
+         --          return []
 
 
 -- TODO:
diff --git a/ECTA/Plugin/Utils.hs b/ECTA/Plugin/Utils.hs
--- a/ECTA/Plugin/Utils.hs
+++ b/ECTA/Plugin/Utils.hs
@@ -287,19 +287,17 @@
         terms = case groups Map.!? t of
                   Just r -> r
                   _ -> groups Map.! (pack $ tail $ unpack t)
-            
 
-mtypeToFta :: TypeSkeleton -> Node
-mtypeToFta (TVar "a"  ) = var1
-mtypeToFta (TVar "b"  ) = var2
-mtypeToFta (TVar "c"  ) = var3
-mtypeToFta (TVar "d"  ) = var4
-mtypeToFta (TVar "acc") = varAcc
--- TODO: lift this restriction
-mtypeToFta (TVar v) =
-  error
-    $ "Current implementation only supports function signatures with type variables a, b, c, d, and acc, but got "
-    ++ show v
-mtypeToFta (TFun  t1    t2      ) = arrowType (mtypeToFta t1) (mtypeToFta t2)
-mtypeToFta (TCons "Fun" [t1, t2]) = arrowType (mtypeToFta t1) (mtypeToFta t2)
-mtypeToFta (TCons s     ts      ) = mkDatatype s (map mtypeToFta ts)
+-- | isSafe checks if we can use the type. Sadly ecta doesn't support all
+-- types as of yet, so we fall back to the regulur valid hole-fits.
+isSafe :: TypeSkeleton -> Bool
+isSafe (TVar "a"  ) = True
+isSafe (TVar "b"  ) = True
+isSafe (TVar "c"  ) = True
+isSafe (TVar "d"  ) = True
+isSafe (TVar "acc") = True
+-- We would like to remove this restriction, but ecta does not support it yet.
+isSafe (TVar v) = False
+isSafe (TFun  t1    t2      ) = isSafe t1 && isSafe t2
+isSafe (TCons "Fun" [t1, t2]) = isSafe t1 && isSafe t2
+isSafe (TCons s     ts      ) = all isSafe ts
diff --git a/ecta-plugin.cabal b/ecta-plugin.cabal
--- a/ecta-plugin.cabal
+++ b/ecta-plugin.cabal
@@ -1,7 +1,7 @@
 name: ecta-plugin
 cabal-version: 1.24
 build-type: Simple
-version: 0.1.1.1
+version: 0.1.1.2
 author: Matthías Páll Gissurarson
 maintainer: mpg@mpg.is
 synopsis: Hole-Fit Synthesis using ECTAs