diff --git a/Cabal-tree-diff/src/Data/TreeDiff/Instances/Cabal.hs b/Cabal-tree-diff/src/Data/TreeDiff/Instances/Cabal.hs
index 15fae62649e..a63faa3510c 100644
--- a/Cabal-tree-diff/src/Data/TreeDiff/Instances/Cabal.hs
+++ b/Cabal-tree-diff/src/Data/TreeDiff/Instances/Cabal.hs
@@ -1,4 +1,3 @@
-{-# LANGUAGE CPP #-}
 {-# OPTIONS_GHC -freduction-depth=0 #-}
 {-# OPTIONS_GHC -fno-warn-orphans #-}
 module Data.TreeDiff.Instances.Cabal () where
diff --git a/Cabal-tree-diff/src/Data/TreeDiff/Instances/CabalLanguage.hs b/Cabal-tree-diff/src/Data/TreeDiff/Instances/CabalLanguage.hs
index 78f6a7e5aa8..194ea34df80 100644
--- a/Cabal-tree-diff/src/Data/TreeDiff/Instances/CabalLanguage.hs
+++ b/Cabal-tree-diff/src/Data/TreeDiff/Instances/CabalLanguage.hs
@@ -1,4 +1,3 @@
-{-# LANGUAGE CPP #-}
 {-# OPTIONS_GHC -freduction-depth=0 #-}
 {-# OPTIONS_GHC -fno-warn-orphans #-}
 module Data.TreeDiff.Instances.CabalLanguage () where
diff --git a/Cabal-tree-diff/src/Data/TreeDiff/Instances/CabalSPDX.hs b/Cabal-tree-diff/src/Data/TreeDiff/Instances/CabalSPDX.hs
index 2926129cb3d..520cbf8c894 100644
--- a/Cabal-tree-diff/src/Data/TreeDiff/Instances/CabalSPDX.hs
+++ b/Cabal-tree-diff/src/Data/TreeDiff/Instances/CabalSPDX.hs
@@ -1,4 +1,3 @@
-{-# LANGUAGE CPP #-}
 {-# OPTIONS_GHC -freduction-depth=0 #-}
 {-# OPTIONS_GHC -fno-warn-orphans #-}
 module Data.TreeDiff.Instances.CabalSPDX () where
diff --git a/Cabal-tree-diff/src/Data/TreeDiff/Instances/CabalVersion.hs b/Cabal-tree-diff/src/Data/TreeDiff/Instances/CabalVersion.hs
index 3c2ac454dde..4321fd0bc3d 100644
--- a/Cabal-tree-diff/src/Data/TreeDiff/Instances/CabalVersion.hs
+++ b/Cabal-tree-diff/src/Data/TreeDiff/Instances/CabalVersion.hs
@@ -1,4 +1,3 @@
-{-# LANGUAGE CPP #-}
 {-# OPTIONS_GHC -freduction-depth=0 #-}
 {-# OPTIONS_GHC -fno-warn-orphans #-}
 module Data.TreeDiff.Instances.CabalVersion where