diff --git a/pkgs/by-name/gr/gram/package.nix b/pkgs/by-name/gr/gram/package.nix
index 6d6f84306f33..48a4664be6fd 100644
--- a/pkgs/by-name/gr/gram/package.nix
+++ b/pkgs/by-name/gr/gram/package.nix
@@ -31,7 +31,7 @@
 
 rustPlatform.buildRustPackage (finalAttrs: {
   pname = "gram";
-  version = "2.1.2";
+  version = "2.2.0";
 
   outputs = [
     "out"
@@ -44,7 +44,7 @@ rustPlatform.buildRustPackage (finalAttrs: {
     owner = "GramEditor";
     repo = "gram";
     tag = finalAttrs.version;
-    hash = "sha256-7FzAvC/JMMIFcuTGkL2Ju644UAIsneOMhiDUFnQske4=";
+    hash = "sha256-w0uZ2qAc3Tt6QVRAX97LWW9aOs02fG1SEYCDhpUhinE=";
   };
 
   postPatch = ''
@@ -54,7 +54,7 @@ rustPlatform.buildRustPackage (finalAttrs: {
       --replace-fail '$CARGO_ABOUT_VERSION' '${cargo-about.version}'
   '';
 
-  cargoHash = "sha256-feESY8ALSG3xa906HBc4pOKGerQ1jF7VUxzvUcsZbrY=";
+  cargoHash = "sha256-+lmDbawAIRllC7LzGJ9qPMtHXPd5aMoul47YOA7nfXA=";
 
   __structuredAttrs = true;
 
@@ -71,7 +71,7 @@ rustPlatform.buildRustPackage (finalAttrs: {
   dontUseCmakeConfigure = true;
 
   buildInputs = [
-    libgit2
+    (libgit2.override { withExperimentalSha256 = true; })
     openssl
     sqlite
     zlib
diff --git a/pkgs/by-name/li/libgit2/package.nix b/pkgs/by-name/li/libgit2/package.nix
index bfac9149df06..6ecfe9388430 100644
--- a/pkgs/by-name/li/libgit2/package.nix
+++ b/pkgs/by-name/li/libgit2/package.nix
@@ -17,6 +17,7 @@
   gitstatus,
   llhttp,
   withGssapi ? false,
+  withExperimentalSha256 ? false,
   krb5,
 }:
 
@@ -43,6 +44,7 @@ stdenv.mkDerivation (finalAttrs: {
     "-DUSE_HTTP_PARSER=llhttp"
     "-DUSE_SSH=ON"
     (lib.cmakeBool "USE_GSSAPI" withGssapi)
+    (lib.cmakeBool "EXPERIMENTAL_SHA256" withExperimentalSha256)
     "-DBUILD_SHARED_LIBS=${if staticBuild then "OFF" else "ON"}"
   ]
   ++ lib.optionals stdenv.hostPlatform.isWindows [
@@ -89,6 +91,13 @@ stdenv.mkDerivation (finalAttrs: {
     )
   '';
 
+  postInstall = lib.optionalString withExperimentalSha256 ''
+    # Downstream Rust bindings (git2-rs / git2-sys) expect experimental headers
+    # to be located at 'git2/experimental.h', but upstream libgit2 installs them
+    # into 'git2-experimental/' when EXPERIMENTAL_SHA256 is enabled.
+    ln -s git2-experimental $dev/include/git2
+  '';
+
   passthru.tests = lib.mapAttrs (_: v: v.override { libgit2 = finalAttrs.finalPackage; }) {
     inherit libgit2-glib;
     inherit (python3Packages) pygit2;