diff --git a/CHANGELOG.txt b/CHANGELOG.txt
--- a/CHANGELOG.txt
+++ b/CHANGELOG.txt
@@ -1,3 +1,7 @@
+2018-03-20, 0.6.5:
+	Updated dependencies and code for GHC 8.4.1 and QuickCheck-2.11, thanks
+	again to Mikhail Glushenkov.
+
 2017-05-27, 0.6.4:
 	Updated dependencies for GHC 8.2.1 (release candidate 2) and
 	binary-0.9, thanks to Mikhail Glushenkov for helping with this.
diff --git a/CREDITS.txt b/CREDITS.txt
--- a/CREDITS.txt
+++ b/CREDITS.txt
@@ -1,4 +1,5 @@
 davean
 Gregory Crosswhite
+Mikhail Glushenkov
 Matti Niemenmaa
 Andrzej Rybczak
diff --git a/Data/ListTrie/Base.hs b/Data/ListTrie/Base.hs
--- a/Data/ListTrie/Base.hs
+++ b/Data/ListTrie/Base.hs
@@ -782,11 +782,14 @@
                Just (best,btr) -> fmap (first (best:)) (findMax btr)
 
 -- O(m)
-findSuccessor :: (Boolable (st a), Trie trie st map k, OrdMap map k)
+findSuccessor :: forall trie map st k a .
+                 (Boolable (st a), Trie trie st map k, OrdMap map k)
               => [k] -> trie map k a -> Maybe ([k], a)
 findSuccessor _   tr | null tr = Nothing
 findSuccessor xs_ tr_          = go xs_ tr_
  where
+   go :: (Boolable (st a), Trie trie st map k, OrdMap map k)
+      => [k] -> trie map k a -> Maybe ([k], a)
    go [] tr = do (k,t) <- fst . Map.minViewWithKey . tMap $ tr
                  fmap (first (k:)) (findMin t)
 
@@ -840,10 +843,13 @@
                                else mkTrie v (Map.insert x tr'' m)
 
 -- O(m)
-splitPrefix :: (Alt st a, Trie trie st map k)
+splitPrefix :: forall trie map st k a .
+               (Alt st a, Trie trie st map k)
             => trie map k a -> ([k], st a, trie map k a)
 splitPrefix = go DL.empty
  where
+   go :: (Alt st a, Trie trie st map k)
+      => DL.DList k -> trie map k a -> ([k], st a, trie map k a)
    go xs tr =
       case Map.singletonView (tMap tr) of
            Just (x,tr') -> go (xs `DL.snoc` x) tr'
diff --git a/Data/ListTrie/Patricia/Base.hs b/Data/ListTrie/Patricia/Base.hs
--- a/Data/ListTrie/Patricia/Base.hs
+++ b/Data/ListTrie/Patricia/Base.hs
@@ -1226,11 +1226,14 @@
       error "Data.ListTrie.Patricia.Base.findPredecessor :: internal error"
 
 -- O(m)
-findSuccessor :: (Boolable (st a), Trie trie st map k, OrdMap map k)
+findSuccessor :: forall trie map st k a .
+                 (Boolable (st a), Trie trie st map k, OrdMap map k)
               => [k] -> trie map k a -> Maybe ([k], a)
 findSuccessor _   tr | null tr = Nothing
 findSuccessor xs_ tr_          = go xs_ tr_
  where
+   go :: (Boolable (st a), Trie trie st map k, OrdMap map k)
+      => [k] -> trie map k a -> Maybe ([k], a)
    go xs tr =
       let (_,pre,m) = tParts tr
        in case comparePrefixes (Map.eqCmp m) pre xs of
diff --git a/LICENSE.txt b/LICENSE.txt
--- a/LICENSE.txt
+++ b/LICENSE.txt
@@ -2,7 +2,7 @@
 are held by whoever wrote the code in question: see CREDITS.txt for a list of
 authors.
 
-Copyright (c) 2008-2016 <authors>
+Copyright (c) 2008-2018 <authors>
 All rights reserved.
 
 Redistribution and use in source and binary forms, with or without
diff --git a/list-tries.cabal b/list-tries.cabal
--- a/list-tries.cabal
+++ b/list-tries.cabal
@@ -1,7 +1,7 @@
 Cabal-Version: >= 1.9.2
 
 Name:        list-tries
-Version:     0.6.4
+Version:     0.6.5
 Homepage:    http://iki.fi/matti.niemenmaa/list-tries/
 Synopsis:    Tries and Patricia tries: finite sets and maps for list keys
 Category:    Data, Data Structures
@@ -26,6 +26,9 @@
 Maintainer:   Matti Niemenmaa <matti.niemenmaa+list-tries@iki.fi>
 License:      BSD3
 License-File: LICENSE.txt
+Tested-With:  GHC == 7.0.4, GHC == 7.2.2, GHC == 7.4.2,
+              GHC == 7.6.3, GHC == 7.8.4, GHC == 7.10.3,
+              GHC == 8.0.2, GHC == 8.2.2, GHC == 8.4.1
 
 Build-Type: Simple
 
@@ -41,8 +44,8 @@
   location: https://github.com/Deewiant/list-tries
 
 Library
-   Build-Depends: base       >= 3    && < 4.11
-                , containers >= 0.3  && < 0.6
+   Build-Depends: base       >= 4.3  && < 4.12
+                , containers >= 0.4  && < 0.6
                 , dlist      >= 0.4  && < 0.9
                 , binary     >= 0.5  && < 0.10
 
@@ -90,11 +93,11 @@
    main-is: Main.hs
 
    Build-Depends: list-tries
-                , base                       >= 3   && < 4.11
+                , base                       >= 4.3 && < 4.12
                 , binary                     >= 0.5 && < 0.10
-                , template-haskell           >= 2.3 && < 2.13
+                , template-haskell           >= 2.3 && < 2.14
                 , HUnit                      >= 1.2 && < 1.7
-                , QuickCheck                 >= 2.1 && < 2.10
+                , QuickCheck                 >= 2.1 && < 2.12
                 , test-framework             >= 0.2 && < 0.9
                 , test-framework-hunit       >= 0.2 && < 0.4
                 , test-framework-quickcheck2 >= 0.2 && < 0.4