diff --git a/pkgs/development/libraries/haskell/base64-bytestring/0.1.1.0.nix b/pkgs/development/libraries/haskell/base64-bytestring/0.1.1.0.nix
deleted file mode 100644
index 304889991f05..000000000000
--- a/pkgs/development/libraries/haskell/base64-bytestring/0.1.1.0.nix
+++ /dev/null
@@ -1,17 +0,0 @@
-{ cabal }:
-
-cabal.mkDerivation (self: {
-  pname = "base64-bytestring";
-  version = "0.1.1.0";
-  sha256 = "0vdmwajxg6w924pcsls45bz4bn29xgl3sgvdp2g1jb8f7qb58r7i";
-  meta = {
-    homepage = "https://github.com/bos/base64-bytestring";
-    description = "Fast base64 encoding and deconding for ByteStrings";
-    license = self.stdenv.lib.licenses.bsd3;
-    platforms = self.ghc.meta.platforms;
-    maintainers = [
-      self.stdenv.lib.maintainers.andres
-      self.stdenv.lib.maintainers.simons
-    ];
-  };
-})
diff --git a/pkgs/development/libraries/haskell/base64-bytestring/0.1.0.3.nix b/pkgs/development/libraries/haskell/base64-bytestring/default.nix
similarity index 82%
rename from pkgs/development/libraries/haskell/base64-bytestring/0.1.0.3.nix
rename to pkgs/development/libraries/haskell/base64-bytestring/default.nix
index f974a72347fd..3690c8cff76b 100644
--- a/pkgs/development/libraries/haskell/base64-bytestring/0.1.0.3.nix
+++ b/pkgs/development/libraries/haskell/base64-bytestring/default.nix
@@ -2,8 +2,8 @@
 
 cabal.mkDerivation (self: {
   pname = "base64-bytestring";
-  version = "0.1.0.3";
-  sha256 = "0d4j8b1d8z9qr1y446bfkj764xgilk8gw2frj0wn0717y8knvmx3";
+  version = "0.1.1.1";
+  sha256 = "0j0jns0yf7dv2bx91hayc8hx0pdab7rhkjllmkl8019kf8rx3gwd";
   meta = {
     homepage = "https://github.com/bos/base64-bytestring";
     description = "Fast base64 encoding and deconding for ByteStrings";
diff --git a/pkgs/top-level/haskell-packages.nix b/pkgs/top-level/haskell-packages.nix
index 82f0fd366055..d1162884f90b 100644
--- a/pkgs/top-level/haskell-packages.nix
+++ b/pkgs/top-level/haskell-packages.nix
@@ -456,9 +456,7 @@ let result = let callPackage = x : y : modifyPrio (newScope result.final x y);
 
   base64String = callPackage ../development/libraries/haskell/base64-string {};
 
-  base64Bytestring_0_1_0_3 = callPackage ../development/libraries/haskell/base64-bytestring/0.1.0.3.nix {};
-  base64Bytestring_0_1_1_0 = callPackage ../development/libraries/haskell/base64-bytestring/0.1.1.0.nix {};
-  base64Bytestring = self.base64Bytestring_0_1_0_3; # Version 0.1.1.0 has serious performance issues.
+  base64Bytestring = callPackage ../development/libraries/haskell/base64-bytestring {};
 
   baseUnicodeSymbols = callPackage ../development/libraries/haskell/base-unicode-symbols {};