diff --git a/pred-trie.cabal b/pred-trie.cabal
--- a/pred-trie.cabal
+++ b/pred-trie.cabal
@@ -1,5 +1,5 @@
 Name:                   pred-trie
-Version:                0.2.1
+Version:                0.2.3
 Author:                 Athan Clark <athan.clark@gmail.com>
 Maintainer:             Athan Clark <athan.clark@gmail.com>
 License:                BSD3
diff --git a/src/Data/Trie/Pred/Unified.hs b/src/Data/Trie/Pred/Unified.hs
--- a/src/Data/Trie/Pred/Unified.hs
+++ b/src/Data/Trie/Pred/Unified.hs
@@ -1,5 +1,6 @@
 module Data.Trie.Pred.Unified
   ( RUPTrie (..)
+  , UPTrie (..)
   , assignLit
   , showTrie
   , merge
@@ -88,7 +89,7 @@
   firstJust $ (NU.lookupNearestParent (NE.fromList ts) <$> xs) ++ [mx]
 
 -- | Append contents up-to lookup path.
-lookupThrough :: (Eq t, Monoid x) => [t] -> RUPTrie t x -> [x]
+lookupThrough :: (Eq t) => [t] -> RUPTrie t x -> [x]
 lookupThrough [] (Rooted mx _) = maybeToList mx
 lookupThrough ts (Rooted mx xs) =
   maybeToList mx ++ NU.firstNonEmpty (NU.lookupThrough (NE.fromList ts) <$> xs)