diff --git a/changelog.md b/changelog.md
--- a/changelog.md
+++ b/changelog.md
@@ -1,5 +1,27 @@
 # Changelog for [`containers` package](http://github.com/haskell/containers)
 
+## [0.6.4.1]
+
+### Bug fixes
+
+* [Replace value-forcing variants of `compose` with lazy variants.](https://github.com/haskell/containers/pull/745)
+  *  This brings `compose` closer in line with functions like `union` and `intersection` which don't evaluate any map values. (Thanks, Simon Jakobi)
+
+### Additions
+
+* [Add `reverseTopSort` to `Data.Graph`](https://github.com/haskell/containers/pull/638) (Thanks, James Parker)
+
+* [Expose `traverseMaybeWithKey` from `Data.IntMap.{Lazy,Strict}`](https://github.com/haskell/containers/pull/743) (Thanks, Simon
+  Jakobi)
+
+### Other changes
+
+* Improvements to the testsuite: [#663](https://github.com/haskell/containers/pull/663), [#662](https://github.com/haskell/containers/pull/662) (Thanks, Bertram Felgenhauer)
+
+* [Fix build with `stack test`](https://github.com/haskell/containers/pull/738) (Thanks, Simon Jakobi)
+
+[0.6.4.1]: https://github.com/haskell/containers/compare/v0.6.3.1-release...v0.6.4.1
+
 ## 0.6.3.1
 
 ### Bug fixes
diff --git a/containers.cabal b/containers.cabal
--- a/containers.cabal
+++ b/containers.cabal
@@ -1,5 +1,5 @@
 name: containers
-version: 0.6.3.1
+version: 0.6.4.1
 license: BSD3
 license-file: LICENSE
 maintainer: libraries@haskell.org
@@ -25,7 +25,7 @@
     include/containers.h
     changelog.md
 
-tested-with: GHC==8.8.2, GHC==8.6.5, GHC==8.4.4, GHC==8.2.2, GHC==8.0.2, GHC==7.10.3, GHC==7.8.4, GHC==7.6.3
+tested-with: GHC==8.10.1, GHC==8.8.2, GHC==8.6.5, GHC==8.4.4, GHC==8.2.2, GHC==8.0.2, GHC==7.10.3, GHC==7.8.4, GHC==7.6.3
 
 source-repository head
     type:     git
diff --git a/src/Data/Graph.hs b/src/Data/Graph.hs
--- a/src/Data/Graph.hs
+++ b/src/Data/Graph.hs
@@ -67,6 +67,7 @@
     , dfs
     , dff
     , topSort
+    , reverseTopSort
     , components
     , scc
     , bcc
@@ -616,6 +617,12 @@
 -- precedes /j/ whenever /j/ is reachable from /i/ but not vice versa.
 topSort      :: Graph -> [Vertex]
 topSort       = reverse . postOrd
+
+-- | Reverse ordering of `topSort`.
+--
+-- @since 0.6.4
+reverseTopSort :: Graph -> [Vertex]
+reverseTopSort = postOrd
 
 ------------------------------------------------------------
 -- Algorithm 3: connected components
diff --git a/src/Data/IntMap/Internal.hs b/src/Data/IntMap/Internal.hs
--- a/src/Data/IntMap/Internal.hs
+++ b/src/Data/IntMap/Internal.hs
@@ -783,6 +783,10 @@
 -- ('compose' bc ab '!?') = (bc '!?') <=< (ab '!?')
 -- @
 --
+-- __Note:__ Prior to v0.6.4, "Data.IntMap.Strict" exposed a version of
+-- 'compose' that forced the values of the output 'IntMap'. This version does
+-- not force these values.
+--
 -- @since 0.6.3.1
 compose :: IntMap c -> IntMap Int -> IntMap c
 compose bc !ab
@@ -1891,6 +1895,8 @@
 
 
 -- | /O(n)/. Traverse keys\/values and collect the 'Just' results.
+--
+-- @since 0.6.4
 traverseMaybeWithKey
   :: Applicative f => (Key -> a -> f (Maybe b)) -> IntMap a -> f (IntMap b)
 traverseMaybeWithKey f = go
diff --git a/src/Data/IntMap/Lazy.hs b/src/Data/IntMap/Lazy.hs
--- a/src/Data/IntMap/Lazy.hs
+++ b/src/Data/IntMap/Lazy.hs
@@ -157,6 +157,7 @@
     , IM.map
     , mapWithKey
     , traverseWithKey
+    , traverseMaybeWithKey
     , mapAccum
     , mapAccumWithKey
     , mapAccumRWithKey
diff --git a/src/Data/IntMap/Strict.hs b/src/Data/IntMap/Strict.hs
--- a/src/Data/IntMap/Strict.hs
+++ b/src/Data/IntMap/Strict.hs
@@ -176,6 +176,7 @@
     , map
     , mapWithKey
     , traverseWithKey
+    , traverseMaybeWithKey
     , mapAccum
     , mapAccumWithKey
     , mapAccumRWithKey
diff --git a/src/Data/IntMap/Strict/Internal.hs b/src/Data/IntMap/Strict/Internal.hs
--- a/src/Data/IntMap/Strict/Internal.hs
+++ b/src/Data/IntMap/Strict/Internal.hs
@@ -293,6 +293,7 @@
   , foldrWithKey'
   , keysSet
   , mergeWithKey'
+  , compose
   , delete
   , deleteMin
   , deleteMax
@@ -719,27 +720,6 @@
   = mergeWithKey' bin (\(Tip k1 x1) (Tip _k2 x2) -> Tip k1 $! f k1 x1 x2) (const Nil) (const Nil) m1 m2
 
 {--------------------------------------------------------------------
-  Compose
---------------------------------------------------------------------}
--- | Relate the keys of one map to the values of
--- the other, by using the values of the former as keys for lookups
--- in the latter.
---
--- Complexity: \( O(n * \min(m,W)) \), where \(m\) is the size of the first argument
---
--- > compose (fromList [('a', "A"), ('b', "B")]) (fromList [(1,'a'),(2,'b'),(3,'z')]) = fromList [(1,"A"),(2,"B")]
---
--- @
--- ('compose' bc ab '!?') = (bc '!?') <=< (ab '!?')
--- @
---
--- @since 0.6.3.1
-compose :: IntMap c -> IntMap Int -> IntMap c
-compose bc !ab
-  | null bc = empty
-  | otherwise = mapMaybe (bc !?) ab
-
-{--------------------------------------------------------------------
   MergeWithKey
 --------------------------------------------------------------------}
 
@@ -923,6 +903,8 @@
 {-# INLINE traverseWithKey #-}
 
 -- | /O(n)/. Traverse keys\/values and collect the 'Just' results.
+--
+-- @since 0.6.4
 traverseMaybeWithKey
   :: Applicative f => (Key -> a -> f (Maybe b)) -> IntMap a -> f (IntMap b)
 traverseMaybeWithKey f = go
diff --git a/src/Data/Map/Internal.hs b/src/Data/Map/Internal.hs
--- a/src/Data/Map/Internal.hs
+++ b/src/Data/Map/Internal.hs
@@ -2106,6 +2106,10 @@
 -- ('compose' bc ab '!?') = (bc '!?') <=< (ab '!?')
 -- @
 --
+-- __Note:__ Prior to v0.6.4, "Data.Map.Strict" exposed a version of
+-- 'compose' that forced the values of the output 'Map'. This version does not
+-- force these values.
+--
 -- @since 0.6.3.1
 compose :: Ord b => Map b c -> Map a b -> Map a c
 compose bc !ab
diff --git a/src/Data/Map/Strict/Internal.hs b/src/Data/Map/Strict/Internal.hs
--- a/src/Data/Map/Strict/Internal.hs
+++ b/src/Data/Map/Strict/Internal.hs
@@ -335,6 +335,7 @@
   , balance
   , balanceL
   , balanceR
+  , compose
   , elemAt
   , elems
   , empty
@@ -854,6 +855,8 @@
 --
 -- Note: 'alterF' is a flipped version of the @at@ combinator from
 -- @Control.Lens.At@.
+--
+-- @since 0.5.8
 alterF :: (Functor f, Ord k)
        => (Maybe a -> f (Maybe a)) -> k -> Map k a -> f (Map k a)
 alterF f k m = atKeyImpl Strict k f m
@@ -1202,27 +1205,6 @@
 forceMaybe Nothing = Nothing
 forceMaybe m@(Just !_) = m
 {-# INLINE forceMaybe #-}
-
-{--------------------------------------------------------------------
-  Compose
---------------------------------------------------------------------}
--- | Relate the keys of one map to the values of
--- the other, by using the values of the former as keys for lookups
--- in the latter.
---
--- Complexity: \( O (n * \log(m)) \), where \(m\) is the size of the first argument
---
--- > compose (fromList [('a', "A"), ('b', "B")]) (fromList [(1,'a'),(2,'b'),(3,'z')]) = fromList [(1,"A"),(2,"B")]
---
--- @
--- ('compose' bc ab '!?') = (bc '!?') <=< (ab '!?')
--- @
---
--- @since 0.6.3.1
-compose :: Ord b => Map b c -> Map a b -> Map a c
-compose bc !ab
-  | null bc = empty
-  | otherwise = mapMaybe (bc !?) ab
 
 {--------------------------------------------------------------------
   MergeWithKey