diff --git a/Cargo.lock b/Cargo.lock
index 41ddb4e7e..e437d8b9c 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -429,6 +429,15 @@ version = "0.6.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "cbd0f76e066e64fdc5631e3bb46381254deab9ef1158292f27c8c57e3bf3fe59"
 
+[[package]]
+name = "cmake"
+version = "0.1.52"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c682c223677e0e5b6b7f63a64b9351844c3f1b1678a68b7ee617e30fb082620e"
+dependencies = [
+ "cc",
+]
+
 [[package]]
 name = "colorchoice"
 version = "1.0.2"
@@ -756,6 +765,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "324a1be68054ef05ad64b861cc9eaf1d623d2d8cb25b4bf2cb9cdd902b4bf253"
 dependencies = [
  "crc32fast",
+ "libz-ng-sys",
  "miniz_oxide 0.8.0",
 ]
 
@@ -1139,6 +1149,7 @@ dependencies = [
  "once_cell",
  "parking_lot",
  "prodash",
+ "sha1",
  "sha1_smol",
  "thiserror 2.0.4",
  "walkdir",
@@ -2010,6 +2021,16 @@ dependencies = [
  "vcpkg",
 ]
 
+[[package]]
+name = "libz-ng-sys"
+version = "1.1.16"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4436751a01da56f1277f323c80d584ffad94a3d14aecd959dd0dff75aa73a438"
+dependencies = [
+ "cmake",
+ "libc",
+]
+
 [[package]]
 name = "libz-sys"
 version = "1.1.20"
@@ -2870,6 +2891,27 @@ dependencies = [
  "serde",
 ]
 
+[[package]]
+name = "sha1"
+version = "0.10.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e3bf829a2d51ab4a5ddf1352d8470c140cadc8301b2ae1789db023f01cedd6ba"
+dependencies = [
+ "cfg-if",
+ "cpufeatures",
+ "digest",
+ "sha1-asm",
+]
+
+[[package]]
+name = "sha1-asm"
+version = "0.5.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "286acebaf8b67c1130aedffad26f594eff0c1292389158135327d2e23aed582b"
+dependencies = [
+ "cc",
+]
+
 [[package]]
 name = "sha1_smol"
 version = "1.0.1"
diff --git a/Cargo.toml b/Cargo.toml
index fabddd4cc..afaf35d70 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -61,7 +61,7 @@ gix = { version = "0.68.0", default-features = false, features = [
     "attributes",
     "blob-diff",
     "index",
-    "max-performance-safe",
+    "max-performance",
 ] }
 glob = "0.3.1"
 hashbrown = { version = "0.15.2", default-features = false, features = ["inline-more"] }
diff --git a/flake.nix b/flake.nix
index a55062799..5d10564ce 100644
--- a/flake.nix
+++ b/flake.nix
@@ -100,8 +100,12 @@
             makeWrapper
             pkg-config
 
+            # for libz-ng-sys (zlib-ng)
+            # TODO: switch to the packaged zlib-ng and drop this dependency
+            cmake
+
             # for signing tests
-            gnupg 
+            gnupg
             openssh
           ] ++ linuxNativeDeps;
           buildInputs = with pkgs; [
@@ -185,6 +189,10 @@
           # In case you need to run `cargo run --bin gen-protos`
           protobuf
 
+          # for libz-ng-sys (zlib-ng)
+          # TODO: switch to the packaged zlib-ng and drop this dependency
+          cmake
+
           # To run the signing tests
           gnupg
           openssh