diff --git a/manifest.dhall b/manifest.dhall
index fa91335dcc40b6e34cfb17686a497482cd4c125b..65ca55900b8a0b47e330726bf6135f08b109aaa1 100644
--- a/manifest.dhall
+++ b/manifest.dhall
@@ -98,6 +98,7 @@ in  [ callHackage "Cabal" "3.8.1.0"
     , callHackage "base-orphans" "0.8.7"
     , callHackage "basement" "0.0.15"
     , callHackage "base16-bytestring" "1.0.2.0"
+    , callHackage "base64-bytestring" "1.2.1.0"
     , callHackage "base64" "0.4.2.4"
     , callHackage "base-compat" "0.12.2"
     , callHackage "base-compat-batteries" "0.12.2"
diff --git a/overlay.nix b/overlay.nix
index 9111bd20ba72d091009a9a595afe4ddf849b355c..19f802062ee88c4aa16c4a36bbffd812e6f5caa4 100644
--- a/overlay.nix
+++ b/overlay.nix
@@ -83,6 +83,8 @@ self: with pkgs.haskell.lib; {
 
   base64 = self.callPackage (./pkgs/base64.nix) { };
 
+  base64-bytestring = self.callPackage (./pkgs/base64-bytestring.nix) { };
+
   basement = self.callPackage (./pkgs/basement.nix) { };
 
   bifunctors = self.callPackage (./pkgs/bifunctors.nix) { };
diff --git a/pkgs/base64-bytestring.nix b/pkgs/base64-bytestring.nix
new file mode 100644
index 0000000000000000000000000000000000000000..3774a41db2a2e288c2d1988dcf6ce632036e61d7
--- /dev/null
+++ b/pkgs/base64-bytestring.nix
@@ -0,0 +1,42 @@
+{ mkDerivation
+, base
+, bytestring
+, criterion
+, deepseq
+, HUnit
+, lib
+, QuickCheck
+, test-framework
+, test-framework-hunit
+, test-framework-quickcheck2
+}:
+mkDerivation {
+  pname = "base64-bytestring";
+  version = "1.2.1.0";
+  sha256 = "fbf8ed30edde271eb605352021431d8f1b055f95a56af31fe2eacf6bdfdc49c9";
+  isLibrary = true;
+  isExecutable = false;
+  enableSeparateDataOutput = false;
+  libraryHaskellDepends = [ base bytestring ];
+  testHaskellDepends = [
+    base
+    bytestring
+    HUnit
+    QuickCheck
+    test-framework
+    test-framework-hunit
+    test-framework-quickcheck2
+  ];
+  benchmarkHaskellDepends = [ base bytestring criterion deepseq ];
+  enableLibraryProfiling = false;
+  enableExecutableProfiling = false;
+  doHaddock = false;
+  jailbreak = true;
+  doCheck = false;
+  doBenchmark = false;
+  hyperlinkSource = false;
+  homepage = "https://github.com/haskell/base64-bytestring";
+  description = "Fast base64 encoding and decoding for ByteStrings";
+  license = lib.licenses.bsd3;
+  broken = false;
+}