diff --git a/pkgs/development/libraries/haskell/ShellCheck/default.nix b/pkgs/development/libraries/haskell/ShellCheck/default.nix
index 7f15fa6b30c4..8beca12325b8 100644
--- a/pkgs/development/libraries/haskell/ShellCheck/default.nix
+++ b/pkgs/development/libraries/haskell/ShellCheck/default.nix
@@ -1,3 +1,5 @@
+# This file was auto-generated by cabal2nix. Please do NOT edit manually!
+
 { cabal, json, mtl, parsec, QuickCheck, regexCompat }:
 
 cabal.mkDerivation (self: {
@@ -15,4 +17,3 @@ cabal.mkDerivation (self: {
     platforms = self.ghc.meta.platforms;
   };
 })
-
diff --git a/pkgs/development/libraries/haskell/pdf-toolbox-content/default.nix b/pkgs/development/libraries/haskell/pdf-toolbox-content/default.nix
index fd43a0452db8..f9f631827d89 100644
--- a/pkgs/development/libraries/haskell/pdf-toolbox-content/default.nix
+++ b/pkgs/development/libraries/haskell/pdf-toolbox-content/default.nix
@@ -1,3 +1,5 @@
+# This file was auto-generated by cabal2nix. Please do NOT edit manually!
+
 { cabal, attoparsec, base16Bytestring, ioStreams, pdfToolboxCore
 , text
 }:
diff --git a/pkgs/development/libraries/haskell/pdf-toolbox-core/default.nix b/pkgs/development/libraries/haskell/pdf-toolbox-core/default.nix
index be55101fc2cb..bfccb645fbb2 100644
--- a/pkgs/development/libraries/haskell/pdf-toolbox-core/default.nix
+++ b/pkgs/development/libraries/haskell/pdf-toolbox-core/default.nix
@@ -1,3 +1,5 @@
+# This file was auto-generated by cabal2nix. Please do NOT edit manually!
+
 { cabal, attoparsec, errors, ioStreams, transformers, zlibBindings
 }:
 
diff --git a/pkgs/development/libraries/haskell/pdf-toolbox-document/default.nix b/pkgs/development/libraries/haskell/pdf-toolbox-document/default.nix
index dc1e96823b35..b62d3e92e5ef 100644
--- a/pkgs/development/libraries/haskell/pdf-toolbox-document/default.nix
+++ b/pkgs/development/libraries/haskell/pdf-toolbox-document/default.nix
@@ -1,3 +1,5 @@
+# This file was auto-generated by cabal2nix. Please do NOT edit manually!
+
 { cabal, cipherRc4, cryptohash, ioStreams, pdfToolboxContent
 , pdfToolboxCore, text, transformers
 }: