diff --git a/containers-tests/benchmarks/IntSet.hs b/containers-tests/benchmarks/IntSet.hs
index 1772b68de..119a5feeb 100644
--- a/containers-tests/benchmarks/IntSet.hs
+++ b/containers-tests/benchmarks/IntSet.hs
@@ -1,4 +1,3 @@
-{-# LANGUAGE CPP #-}
 {-# LANGUAGE BangPatterns, GeneralizedNewtypeDeriving #-}
 
 module Main where
diff --git a/containers-tests/benchmarks/Map.hs b/containers-tests/benchmarks/Map.hs
index f88d8978e..bd886cbdc 100644
--- a/containers-tests/benchmarks/Map.hs
+++ b/containers-tests/benchmarks/Map.hs
@@ -1,4 +1,3 @@
-{-# LANGUAGE CPP #-}
 {-# LANGUAGE BangPatterns #-}
 module Main where
 
diff --git a/containers-tests/tests/bitqueue-properties.hs b/containers-tests/tests/bitqueue-properties.hs
index 95ce473a3..6558b7016 100644
--- a/containers-tests/tests/bitqueue-properties.hs
+++ b/containers-tests/tests/bitqueue-properties.hs
@@ -1,4 +1,3 @@
-{-# LANGUAGE CPP #-}
 {-# LANGUAGE BangPatterns #-}
 
 import qualified Data.List as List
diff --git a/containers-tests/tests/intmap-strictness.hs b/containers-tests/tests/intmap-strictness.hs
index e09bcad41..bba264c38 100644
--- a/containers-tests/tests/intmap-strictness.hs
+++ b/containers-tests/tests/intmap-strictness.hs
@@ -1,4 +1,3 @@
-{-# LANGUAGE CPP #-}
 {-# LANGUAGE BangPatterns #-}
 {-# OPTIONS_GHC -fno-warn-orphans #-}
 
diff --git a/containers-tests/tests/intset-properties.hs b/containers-tests/tests/intset-properties.hs
index 2af3e3ea8..e5b0d8cbe 100644
--- a/containers-tests/tests/intset-properties.hs
+++ b/containers-tests/tests/intset-properties.hs
@@ -1,4 +1,3 @@
-{-# LANGUAGE CPP #-}
 import Control.Applicative (Const(..))
 import Data.Bits ((.&.), popCount)
 import Data.Word (Word)
diff --git a/containers-tests/tests/seq-properties.hs b/containers-tests/tests/seq-properties.hs
index a3db6bca1..273877b6e 100644
--- a/containers-tests/tests/seq-properties.hs
+++ b/containers-tests/tests/seq-properties.hs
@@ -2,8 +2,6 @@
 {-# LANGUAGE PatternGuards #-}
 {-# LANGUAGE TemplateHaskell #-}
 
-#include "containers.h"
-
 import Data.Sequence.Internal
   ( Sized (..)
   , Seq (Seq)
diff --git a/containers-tests/tests/set-properties.hs b/containers-tests/tests/set-properties.hs
index a6c884113..3ad68d751 100644
--- a/containers-tests/tests/set-properties.hs
+++ b/containers-tests/tests/set-properties.hs
@@ -1,4 +1,3 @@
-{-# LANGUAGE CPP #-}
 import qualified Data.IntSet as IntSet
 import Data.List (nub, sort, sortBy)
 import qualified Data.List as List
diff --git a/containers/src/Data/IntMap.hs b/containers/src/Data/IntMap.hs
index 32b93dcfb..2fba64a57 100644
--- a/containers/src/Data/IntMap.hs
+++ b/containers/src/Data/IntMap.hs
@@ -3,8 +3,6 @@
 {-# LANGUAGE Safe #-}
 #endif
 
-#include "containers.h"
-
 -----------------------------------------------------------------------------
 -- |
 -- Module      :  Data.IntMap
diff --git a/containers/src/Data/IntMap/Internal.hs b/containers/src/Data/IntMap/Internal.hs
index 3532aacf9..fdcd39019 100644
--- a/containers/src/Data/IntMap/Internal.hs
+++ b/containers/src/Data/IntMap/Internal.hs
@@ -13,8 +13,6 @@
 {-# OPTIONS_HADDOCK not-home #-}
 {-# OPTIONS_GHC -fno-warn-incomplete-uni-patterns #-}
 
-#include "containers.h"
-
 -----------------------------------------------------------------------------
 -- |
 -- Module      :  Data.IntMap.Internal
diff --git a/containers/src/Data/IntMap/Lazy.hs b/containers/src/Data/IntMap/Lazy.hs
index d148839bb..7be9b7030 100644
--- a/containers/src/Data/IntMap/Lazy.hs
+++ b/containers/src/Data/IntMap/Lazy.hs
@@ -3,8 +3,6 @@
 {-# LANGUAGE Safe #-}
 #endif
 
-#include "containers.h"
-
 -----------------------------------------------------------------------------
 -- |
 -- Module      :  Data.IntMap.Lazy
diff --git a/containers/src/Data/IntMap/Merge/Lazy.hs b/containers/src/Data/IntMap/Merge/Lazy.hs
index 5ff13fe05..1d903898b 100644
--- a/containers/src/Data/IntMap/Merge/Lazy.hs
+++ b/containers/src/Data/IntMap/Merge/Lazy.hs
@@ -3,8 +3,6 @@
 {-# LANGUAGE Safe #-}
 #endif
 
-#include "containers.h"
-
 -----------------------------------------------------------------------------
 -- |
 -- Module      :  Data.IntMap.Merge.Lazy
diff --git a/containers/src/Data/IntMap/Merge/Strict.hs b/containers/src/Data/IntMap/Merge/Strict.hs
index e17770959..2819f940c 100644
--- a/containers/src/Data/IntMap/Merge/Strict.hs
+++ b/containers/src/Data/IntMap/Merge/Strict.hs
@@ -4,8 +4,6 @@
 {-# LANGUAGE Trustworthy #-}
 #endif
 
-#include "containers.h"
-
 -----------------------------------------------------------------------------
 -- |
 -- Module      :  Data.IntMap.Merge.Strict
diff --git a/containers/src/Data/IntMap/Strict.hs b/containers/src/Data/IntMap/Strict.hs
index 4785e6713..c93dd9732 100644
--- a/containers/src/Data/IntMap/Strict.hs
+++ b/containers/src/Data/IntMap/Strict.hs
@@ -3,8 +3,6 @@
 {-# LANGUAGE Trustworthy #-}
 #endif
 
-#include "containers.h"
-
 -----------------------------------------------------------------------------
 -- |
 -- Module      :  Data.IntMap.Strict
diff --git a/containers/src/Data/IntMap/Strict/Internal.hs b/containers/src/Data/IntMap/Strict/Internal.hs
index 414f9b586..78312fdde 100644
--- a/containers/src/Data/IntMap/Strict/Internal.hs
+++ b/containers/src/Data/IntMap/Strict/Internal.hs
@@ -4,8 +4,6 @@
 
 {-# OPTIONS_GHC -fno-warn-incomplete-uni-patterns #-}
 
-#include "containers.h"
-
 -----------------------------------------------------------------------------
 -- |
 -- Module      :  Data.IntMap.Strict.Internal
diff --git a/containers/src/Data/IntSet.hs b/containers/src/Data/IntSet.hs
index cc4924b6b..11f5079c5 100644
--- a/containers/src/Data/IntSet.hs
+++ b/containers/src/Data/IntSet.hs
@@ -3,8 +3,6 @@
 {-# LANGUAGE Safe #-}
 #endif
 
-#include "containers.h"
-
 -----------------------------------------------------------------------------
 -- |
 -- Module      :  Data.IntSet
diff --git a/containers/src/Data/Map.hs b/containers/src/Data/Map.hs
index f2a60c588..60be5946d 100644
--- a/containers/src/Data/Map.hs
+++ b/containers/src/Data/Map.hs
@@ -3,8 +3,6 @@
 {-# LANGUAGE Safe #-}
 #endif
 
-#include "containers.h"
-
 -----------------------------------------------------------------------------
 -- |
 -- Module      :  Data.Map
diff --git a/containers/src/Data/Map/Internal/Debug.hs b/containers/src/Data/Map/Internal/Debug.hs
index a0fb332ec..e42eeffbf 100644
--- a/containers/src/Data/Map/Internal/Debug.hs
+++ b/containers/src/Data/Map/Internal/Debug.hs
@@ -1,6 +1,3 @@
-{-# LANGUAGE CPP #-}
-#include "containers.h"
-
 module Data.Map.Internal.Debug where
 
 import Data.Map.Internal (Map (..), size, delta)
diff --git a/containers/src/Data/Map/Lazy.hs b/containers/src/Data/Map/Lazy.hs
index c08ea4a94..5a01a4914 100644
--- a/containers/src/Data/Map/Lazy.hs
+++ b/containers/src/Data/Map/Lazy.hs
@@ -3,8 +3,6 @@
 {-# LANGUAGE Safe #-}
 #endif
 
-#include "containers.h"
-
 -----------------------------------------------------------------------------
 -- |
 -- Module      :  Data.Map.Lazy
diff --git a/containers/src/Data/Map/Merge/Lazy.hs b/containers/src/Data/Map/Merge/Lazy.hs
index 5ac059ab9..c23a4f03c 100644
--- a/containers/src/Data/Map/Merge/Lazy.hs
+++ b/containers/src/Data/Map/Merge/Lazy.hs
@@ -3,8 +3,6 @@
 {-# LANGUAGE Safe #-}
 #endif
 
-#include "containers.h"
-
 -----------------------------------------------------------------------------
 -- |
 -- Module      :  Data.Map.Merge.Lazy
diff --git a/containers/src/Data/Map/Merge/Strict.hs b/containers/src/Data/Map/Merge/Strict.hs
index 1cc8954a9..d4181bbbe 100644
--- a/containers/src/Data/Map/Merge/Strict.hs
+++ b/containers/src/Data/Map/Merge/Strict.hs
@@ -3,8 +3,6 @@
 {-# LANGUAGE Safe #-}
 #endif
 
-#include "containers.h"
-
 -----------------------------------------------------------------------------
 -- |
 -- Module      :  Data.Map.Merge.Strict
diff --git a/containers/src/Data/Map/Strict.hs b/containers/src/Data/Map/Strict.hs
index d104dfd59..97fe9f9b1 100644
--- a/containers/src/Data/Map/Strict.hs
+++ b/containers/src/Data/Map/Strict.hs
@@ -3,8 +3,6 @@
 {-# LANGUAGE Safe #-}
 #endif
 
-#include "containers.h"
-
 -----------------------------------------------------------------------------
 -- |
 -- Module      :  Data.Map.Strict
diff --git a/containers/src/Data/Map/Strict/Internal.hs b/containers/src/Data/Map/Strict/Internal.hs
index 1c9a97368..f9b231319 100644
--- a/containers/src/Data/Map/Strict/Internal.hs
+++ b/containers/src/Data/Map/Strict/Internal.hs
@@ -5,8 +5,6 @@
 #endif
 {-# OPTIONS_HADDOCK not-home #-}
 
-#include "containers.h"
-
 -----------------------------------------------------------------------------
 -- |
 -- Module      :  Data.Map.Strict.Internal
diff --git a/containers/src/Data/Set.hs b/containers/src/Data/Set.hs
index 8831c0a7b..b920cefa9 100644
--- a/containers/src/Data/Set.hs
+++ b/containers/src/Data/Set.hs
@@ -3,8 +3,6 @@
 {-# LANGUAGE Safe #-}
 #endif
 
-#include "containers.h"
-
 -----------------------------------------------------------------------------
 -- |
 -- Module      :  Data.Set
diff --git a/containers/src/Data/Set/Internal.hs b/containers/src/Data/Set/Internal.hs
index 8697cdf80..285b2720f 100644
--- a/containers/src/Data/Set/Internal.hs
+++ b/containers/src/Data/Set/Internal.hs
@@ -11,8 +11,6 @@
 
 {-# OPTIONS_HADDOCK not-home #-}
 
-#include "containers.h"
-
 -----------------------------------------------------------------------------
 -- |
 -- Module      :  Data.Set.Internal
diff --git a/containers/src/Data/Tree.hs b/containers/src/Data/Tree.hs
index 0f164f24b..5c5fe1bfa 100644
--- a/containers/src/Data/Tree.hs
+++ b/containers/src/Data/Tree.hs
@@ -8,8 +8,6 @@
 {-# LANGUAGE Trustworthy #-}
 #endif
 
-#include "containers.h"
-
 -----------------------------------------------------------------------------
 -- |
 -- Module      :  Data.Tree
diff --git a/containers/src/Utils/Containers/Internal/BitQueue.hs b/containers/src/Utils/Containers/Internal/BitQueue.hs
index 43781a50e..f7618c8d2 100644
--- a/containers/src/Utils/Containers/Internal/BitQueue.hs
+++ b/containers/src/Utils/Containers/Internal/BitQueue.hs
@@ -1,8 +1,5 @@
-{-# LANGUAGE CPP #-}
 {-# LANGUAGE BangPatterns #-}
 
-#include "containers.h"
-
 -----------------------------------------------------------------------------
 -- |
 -- Module      :  Utils.Containers.Internal.BitQueue
diff --git a/containers/src/Utils/Containers/Internal/BitUtil.hs b/containers/src/Utils/Containers/Internal/BitUtil.hs
index e82d29e5b..1edf044aa 100644
--- a/containers/src/Utils/Containers/Internal/BitUtil.hs
+++ b/containers/src/Utils/Containers/Internal/BitUtil.hs
@@ -4,8 +4,6 @@
 {-# LANGUAGE Trustworthy #-}
 #endif
 
-#include "containers.h"
-
 -----------------------------------------------------------------------------
 -- |
 -- Module      :  Utils.Containers.Internal.BitUtil
diff --git a/containers/src/Utils/Containers/Internal/State.hs b/containers/src/Utils/Containers/Internal/State.hs
index 96b898b38..e2c0b051e 100644
--- a/containers/src/Utils/Containers/Internal/State.hs
+++ b/containers/src/Utils/Containers/Internal/State.hs
@@ -1,5 +1,3 @@
-{-# LANGUAGE CPP #-}
-#include "containers.h"
 {-# OPTIONS_HADDOCK hide #-}
 
 -- | A clone of Control.Monad.State.Strict.