diff --git a/pkgs/development/libraries/haskell/attoparsec/default.nix b/pkgs/development/libraries/haskell/attoparsec/default.nix
index 8d3e53cd2ea..536b27833a2 100644
--- a/pkgs/development/libraries/haskell/attoparsec/default.nix
+++ b/pkgs/development/libraries/haskell/attoparsec/default.nix
@@ -1,9 +1,10 @@
-{cabal}:
+{cabal, deepseq}:
 
 cabal.mkDerivation (self : {
   pname = "attoparsec";
-  version = "0.8.5.0";
-  sha256 = "0rdhjqgbbasc1diqzjdb6a8s46kcpdw5yxq2vkg3y2z71zln0a31";
+  version = "0.9.1.1";
+  sha256 = "1qkkl9pzk4znqh34pchmxbcslybvii35lkxhwf6445lyhj20356b";
+  propagatedBuildInputs = [deepseq];
   meta = {
     description = "Fast combinator parsing for bytestrings";
     license = "BSD3";
diff --git a/pkgs/development/libraries/haskell/attoparsec/enumerator.nix b/pkgs/development/libraries/haskell/attoparsec/enumerator.nix
index 95a06a09da5..4152cd4ed2c 100644
--- a/pkgs/development/libraries/haskell/attoparsec/enumerator.nix
+++ b/pkgs/development/libraries/haskell/attoparsec/enumerator.nix
@@ -2,8 +2,8 @@
 
 cabal.mkDerivation (self : {
   pname = "attoparsec-enumerator";
-  version = "0.2.0.3";
-  sha256 = "02v9cwq1jbn0179zd2cky4ix6ykrkd7cpw38c1x7zgy0pal42x4v";
+  version = "0.2.0.4";
+  sha256 = "14v53vppcf4k3m4kid10pg5r3zsn894f36w1y2pzlc72w81fv3gd";
   propagatedBuildInputs = [attoparsec enumerator];
   meta = {
     description = "Converts an Attoparsec parser into an iteratee";