diff --git a/pkgs/development/ocaml-modules/bstr/default.nix b/pkgs/development/ocaml-modules/bstr/default.nix
new file mode 100644
index 000000000000..37e342db4400
--- /dev/null
+++ b/pkgs/development/ocaml-modules/bstr/default.nix
@@ -0,0 +1,24 @@
+{
+  fetchurl,
+  buildDunePackage,
+  lib,
+}:
+
+buildDunePackage rec {
+  pname = "bstr";
+  version = "0.0.2";
+
+  minimalOCamlVersion = "4.13";
+
+  src = fetchurl {
+    url = "https://github.com/robur-coop/bstr/releases/download/v${version}/bstr-${version}.tbz";
+    hash = "sha256-/zvzCBzT014OesTmxGBDB98ZRU++YNDLUZ8uaDK3keM=";
+  };
+
+  meta = {
+    description = "A simple library for bigstrings";
+    homepage = "https://git.robur.coop/robur/bstr";
+    license = lib.licenses.mit;
+    maintainers = [ lib.maintainers.vbgl ];
+  };
+}
diff --git a/pkgs/development/ocaml-modules/git/paf.nix b/pkgs/development/ocaml-modules/git/paf.nix
index 55ab06726049..0867363720ca 100644
--- a/pkgs/development/ocaml-modules/git/paf.nix
+++ b/pkgs/development/ocaml-modules/git/paf.nix
@@ -23,6 +23,11 @@ buildDunePackage {
 
   inherit (git) version src;
 
+  postPatch = ''
+    substituteInPlace src/git-paf/dune --replace-fail bigstringaf 'bigstringaf bstr'
+    substituteInPlace src/git-paf/git_paf.ml --replace-fail Bigstringaf.t Bstr.t
+  '';
+
   minimalOCamlVersion = "4.08";
 
   propagatedBuildInputs = [
diff --git a/pkgs/development/ocaml-modules/h1/default.nix b/pkgs/development/ocaml-modules/h1/default.nix
index 0f7fdebff65c..aad1f760a65b 100644
--- a/pkgs/development/ocaml-modules/h1/default.nix
+++ b/pkgs/development/ocaml-modules/h1/default.nix
@@ -3,11 +3,12 @@
   buildDunePackage,
   fetchurl,
   angstrom,
-  bigstringaf,
+  base64,
+  bstr,
   faraday,
   httpun-types,
   alcotest,
-  version ? "1.0.0",
+  version ? "1.1.0",
 }:
 
 buildDunePackage {
@@ -17,12 +18,13 @@ buildDunePackage {
 
   src = fetchurl {
     url = "https://github.com/robur-coop/ocaml-h1/releases/download/v${version}/h1-${version}.tbz";
-    hash = "sha256-uFHRcNmfHiFmdMAMKiS5KilIwMylf/AoJCfxllrIvRM=";
+    hash = "sha256-LTBn7TgBY5IBSfvpFJ1b2mMLT0XjwQvnk77qBqB8bTw=";
   };
 
   propagatedBuildInputs = [
     angstrom
-    bigstringaf
+    base64
+    bstr
     faraday
     httpun-types
   ];
diff --git a/pkgs/top-level/ocaml-packages.nix b/pkgs/top-level/ocaml-packages.nix
index f025e1cfd9f6..2be1c4535a94 100644
--- a/pkgs/top-level/ocaml-packages.nix
+++ b/pkgs/top-level/ocaml-packages.nix
@@ -145,6 +145,8 @@ let
 
         brr = callPackage ../development/ocaml-modules/brr { };
 
+        bstr = callPackage ../development/ocaml-modules/bstr { };
+
         bwd = callPackage ../development/ocaml-modules/bwd { };
 
         bytesrw = callPackage ../development/ocaml-modules/bytesrw { };