diff --git a/.github/workflows/CI.yml b/.github/workflows/CI.yml
index a3213a8..9b033d5 100644
--- a/.github/workflows/CI.yml
+++ b/.github/workflows/CI.yml
@@ -17,18 +17,23 @@ jobs:
         with:
           python-version: ${{ matrix.py_version }}
           architecture: x64
+      - name: Install llvm-17
+        run: brew install llvm@17
       - name: Install Rust toolchain
         uses: actions-rs/toolchain@v1
         with:
           toolchain: stable
           default: true
-      - name: Build wheels - universal2
+      - name: Build wheels
         run: |
+          eval "$(brew shellenv)"
           export MACOSX_DEPLOYMENT_TARGET=10.14
+          export LIBCLANG_PATH=${HOMEBREW_PREFIX}/opt/llvm/lib
           rustup target add aarch64-apple-darwin
           pip install maturin
-          maturin build --release --target universal2-apple-darwin --out dist
-      - name: Install built wheel - universal2
+          maturin build --release --target aarch64-apple-darwin --out dist
+          maturin build --release --target x86_64-apple-darwin --out dist
+      - name: Install built wheel
         run: |
           pip install rocksdict --no-index --find-links dist --force-reinstall || true
           pip install speedict --no-index --find-links dist --force-reinstall || true
@@ -57,8 +62,8 @@ jobs:
       - name: Install LLVM and Clang
         uses: KyleMayes/install-llvm-action@v1
         with:
-          version: 11.0
-          directory: ${{ runner.temp }}/llvm-11.0
+          version: 17.0
+          directory: ${{ runner.temp }}/llvm-17.0
       - name: Install Rust toolchain
         uses: actions-rs/toolchain@v1
         with:
@@ -70,7 +75,7 @@ jobs:
           target: ${{ matrix.target }}
           args: --release --out dist
         env:
-          LIBCLANG_PATH: ${{ runner.temp }}/llvm-11.0/lib
+          LIBCLANG_PATH: ${{ runner.temp }}/llvm-17.0/lib
       - name: Install built wheel and test
         run: |
           pip install rocksdict --no-index --find-links dist --force-reinstall || true
diff --git a/.github/workflows/PR.yml b/.github/workflows/PR.yml
index 522fafd..8312e5a 100644
--- a/.github/workflows/PR.yml
+++ b/.github/workflows/PR.yml
@@ -17,18 +17,23 @@ jobs:
         with:
           python-version: ${{ matrix.py_version }}
           architecture: x64
+      - name: Install llvm-17
+        run: brew install llvm@17
       - name: Install Rust toolchain
         uses: actions-rs/toolchain@v1
         with:
           toolchain: stable
           default: true
-      - name: Build wheels - universal2
+      - name: Build wheels
         run: |
+          eval "$(brew shellenv)"
           export MACOSX_DEPLOYMENT_TARGET=10.14
+          export LIBCLANG_PATH=${HOMEBREW_PREFIX}/opt/llvm/lib
           rustup target add aarch64-apple-darwin
           pip install maturin
-          maturin build --release --target universal2-apple-darwin --out dist
-      - name: Install built wheel - universal2
+          maturin build --release --target aarch64-apple-darwin --out dist
+          maturin build --release --target x86_64-apple-darwin --out dist
+      - name: Install built wheel
         run: |
           pip install rocksdict --no-index --find-links dist --force-reinstall || true
           pip install speedict --no-index --find-links dist --force-reinstall || true
@@ -57,8 +62,8 @@ jobs:
       - name: Install LLVM and Clang
         uses: KyleMayes/install-llvm-action@v1
         with:
-          version: 11.0
-          directory: ${{ runner.temp }}/llvm-11.0
+          version: 17.0
+          directory: ${{ runner.temp }}/llvm-17.0
       - name: Install Rust toolchain
         uses: actions-rs/toolchain@v1
         with:
@@ -70,7 +75,7 @@ jobs:
           target: ${{ matrix.target }}
           args: --release --out dist
         env:
-          LIBCLANG_PATH: ${{ runner.temp }}/llvm-11.0/lib
+          LIBCLANG_PATH: ${{ runner.temp }}/llvm-17.0/lib
       - name: Install built wheel and test
         run: |
           pip install rocksdict --no-index --find-links dist --force-reinstall || true
diff --git a/Cargo.toml b/Cargo.toml
index 320461b..d839ebf 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -23,3 +23,9 @@ libc = "0.2.112"
 [dependencies.pyo3]
 version = "0.20"
 features = ["extension-module", "num-bigint"]
+
+[profile.release]
+codegen-units = 1
+debug = false
+lto = true
+opt-level = 3