diff --git a/src/Data/Validity/Map.hs b/src/Data/Validity/Map.hs
--- a/src/Data/Validity/Map.hs
+++ b/src/Data/Validity/Map.hs
@@ -10,9 +10,8 @@
 -- | A 'Map' of things is valid if all the keys and values are valid and the 'Map' itself
 -- is valid.
 instance (Ord k, Validity k, Validity v) => Validity (Map k v) where
-    isValid m = M.valid m && all isValid (M.toList m)
     validate m =
         mconcat
-            [ M.valid m <?@> "The Map structure is valid."
-            , M.toList m <?!> "Map elements"
+            [ declare "The Map structure is valid." $ M.valid m
+            , delve "Map elements" $ M.toList m
             ]
diff --git a/src/Data/Validity/Sequence.hs b/src/Data/Validity/Sequence.hs
--- a/src/Data/Validity/Sequence.hs
+++ b/src/Data/Validity/Sequence.hs
@@ -9,5 +9,4 @@
 
 -- | A 'Seq'uence of things is valid if all the elements are valid.
 instance Validity v => Validity (Seq v) where
-    isValid = all isValid . toList
-    validate s = toList s <?!> "Seq elements"
+    validate s = annotate (toList s) "Seq elements"
diff --git a/src/Data/Validity/Set.hs b/src/Data/Validity/Set.hs
--- a/src/Data/Validity/Set.hs
+++ b/src/Data/Validity/Set.hs
@@ -10,9 +10,8 @@
 -- | A 'Set' of things is valid if all the elements are valid and the 'Set' itself
 -- is valid.
 instance (Ord v, Validity v) => Validity (Set v) where
-    isValid s = S.valid s && all isValid (S.toList s)
     validate s =
         mconcat
-            [ S.valid s <?@> "The set structure is valid."
-            , all isValid (S.toList s) <?!> "Set elements"
+            [ declare "The set structure is valid." $ S.valid s
+            , annotate (S.toList s) "Set elements"
             ]
diff --git a/src/Data/Validity/Tree.hs b/src/Data/Validity/Tree.hs
--- a/src/Data/Validity/Tree.hs
+++ b/src/Data/Validity/Tree.hs
@@ -8,5 +8,5 @@
 
 -- | A 'Tree' of things is valid if all the things in the 'Tree' are valid.
 instance Validity a => Validity (Tree a) where
-    isValid (Node rl sf) = isValid rl && isValid sf
-    validate (Node rl sf) = mconcat [rl <?!> "rootLabel", sf <?!> "subForest"]
+    validate (Node rl sf) =
+        mconcat [annotate rl "rootLabel", annotate sf "subForest"]
diff --git a/validity-containers.cabal b/validity-containers.cabal
--- a/validity-containers.cabal
+++ b/validity-containers.cabal
@@ -1,33 +1,41 @@
-name: validity-containers
-version: 0.2.0.0
-cabal-version: >=1.10
-build-type: Simple
-license: MIT
-license-file: LICENSE
-copyright: Copyright: (c) 2016 Tom Sydney Kerckhove
-maintainer: syd.kerckhove@gmail.com
-homepage: https://github.com/NorfairKing/validity#readme
-synopsis: Validity instances for containers
-description:
-    Please see README.md
-category: Validity
-author: Tom Sydney Kerckhove
+-- This file has been generated from package.yaml by hpack version 0.20.0.
+--
+-- see: https://github.com/sol/hpack
+--
+-- hash: 4b54bc51be2c6a7922f6a1defaeae34d645b035b461c72a701e208c6cf71ebbf
 
+name:           validity-containers
+version:        0.3.0.0
+synopsis:       Validity instances for containers
+description:    Please see README.md
+category:       Validity
+homepage:       https://github.com/NorfairKing/validity#readme
+bug-reports:    https://github.com/NorfairKing/validity/issues
+author:         Tom Sydney Kerckhove
+maintainer:     syd.kerckhove@gmail.com
+copyright:      Copyright: (c) 2016-2018 Tom Sydney Kerckhove
+license:        MIT
+license-file:   LICENSE
+build-type:     Simple
+cabal-version:  >= 1.10
+
 source-repository head
-    type: git
-    location: https://github.com/NorfairKing/validity
+  type: git
+  location: https://github.com/NorfairKing/validity
 
 library
-    exposed-modules:
-        Data.Validity.Containers
-        Data.Validity.Tree
-        Data.Validity.Map
-        Data.Validity.Sequence
-        Data.Validity.Set
-    build-depends:
-        base >=4.7 && <5,
-        validity >=0.4 && <0.5,
-        containers -any
-    default-language: Haskell2010
-    hs-source-dirs: src
-
+  hs-source-dirs:
+      src
+  build-depends:
+      base >=4.7 && <5
+    , containers
+    , validity >=0.5 && <0.6
+  exposed-modules:
+      Data.Validity.Containers
+      Data.Validity.Tree
+      Data.Validity.Map
+      Data.Validity.Sequence
+      Data.Validity.Set
+  other-modules:
+      Paths_validity_containers
+  default-language: Haskell2010