diff --git a/.gitattributes b/.gitattributes
index 650a5619..66bcdac6 100644
--- a/.gitattributes
+++ b/.gitattributes
@@ -1 +1,3 @@
-include linguist-vendored
+include/pyo3/pyo3-build-config/**/* linguist-vendored
+include/pyo3/pyo3-ffi/**/* linguist-vendored
+include/yyjson/* linguist-vendored
diff --git a/.github/workflows/artifact.yaml b/.github/workflows/artifact.yaml
index ecb0cd86..29ea79a8 100644
--- a/.github/workflows/artifact.yaml
+++ b/.github/workflows/artifact.yaml
@@ -40,7 +40,7 @@ jobs:
 
     - run: python3 -m pip install --user -r test/requirements.txt -r integration/requirements.txt mypy
 
-    - run: pytest -s -rxX -v -n 4 test
+    - run: pytest -v test
       env:
         PYTHONMALLOC: "debug"
 
@@ -58,31 +58,30 @@ jobs:
         overwrite: true
         retention-days: 1
 
-  manylinux_2_17_amd64:
+  manylinux_amd64:
     runs-on: ubuntu-24.04
     timeout-minutes: 10
     strategy:
       fail-fast: false
       matrix:
+        python: [
+          { interpreter: 'python3.13', package: 'python3.13', compatibility: "manylinux_2_17" },
+          { interpreter: 'python3.12', package: 'python3.12', compatibility: "manylinux_2_17" },
+          { interpreter: 'python3.11', package: 'python3.11', compatibility: "manylinux_2_17" },
+          { interpreter: 'python3.10', package: 'python3.10', compatibility: "manylinux_2_17" },
+          { interpreter: 'python3.9', package: 'python3.9', compatibility: "manylinux_2_17" },
+        ]
         arch: [
           {
             cc: "clang",
             cflags: "-Os -fstrict-aliasing -fno-plt -flto=full -emit-llvm",
             features: "avx512,no-panic,unstable-simd,yyjson",
             ldflags: "-fuse-ld=lld -Wl,-plugin-opt=also-emit-llvm -Wl,--as-needed -Wl,-zrelro,-znow",
-            rustflags: "-C linker=clang -C link-arg=-fuse-ld=lld -C linker-plugin-lto -C lto=fat -C link-arg=-Wl,-zrelro,-znow -Z mir-opt-level=4 -Z virtual-function-elimination -Z threads=4 -D warnings",
+            rustflags: "-C linker=clang -C link-arg=-fuse-ld=lld -C linker-plugin-lto -C lto=fat -C link-arg=-Wl,-zrelro,-znow -Z mir-opt-level=4 -Z threads=4 -D warnings",
             tag: null,
             target: "x86_64-unknown-linux-gnu",
           },
         ]
-        python: [
-          { interpreter: 'python3.13', package: 'python3.13' },
-          { interpreter: 'python3.12', package: 'python3.12' },
-          { interpreter: 'python3.11', package: 'python3.11' },
-          { interpreter: 'python3.10', package: 'python3.10' },
-          { interpreter: 'python3.9', package: 'python3.9' },
-          { interpreter: 'python3.8', package: 'python3.8' },
-        ]
     env:
       PYTHON: "${{ matrix.python.interpreter }}"
       PYTHON_PACKAGE: "${{ matrix.python.package }}"
@@ -94,6 +93,7 @@ jobs:
       LDFLAGS: "${{ matrix.arch.ldflags }}"
       RUSTFLAGS: "${{ matrix.arch.rustflags }}"
       CARGO_TARGET_DIR: "/tmp/orjson"
+      COMPATIBILITY: "${{ matrix.python.compatibility }}"
     steps:
 
     - name: cpuinfo
@@ -106,6 +106,7 @@ jobs:
       with:
         container: registry.fedoraproject.org/fedora:42
         arch: ${{ matrix.arch.tag }}
+        initial_delay: 5s
         podman_args: "-v .:/orjson -v /tmp:/tmp --workdir /orjson"
 
     - name: setup-shell-wrapper
@@ -128,13 +129,13 @@ jobs:
 
         maturin build --release --strip \
           --features="${FEATURES}" \
-          --compatibility=manylinux_2_17 \
+          --compatibility="${COMPATIBILITY}" \
           --interpreter="${PYTHON}" \
           --target="${TARGET}"
 
         uv pip install ${CARGO_TARGET_DIR}/wheels/orjson*.whl
 
-        pytest -s -rxX -v -n 4 test
+        pytest -v test
         ./integration/run thread
         ./integration/run http
         ./integration/run init
@@ -151,26 +152,26 @@ jobs:
         retention-days: 1
 
 
-  manylinux_2_17_aarch64:
+  manylinux_aarch64:
     runs-on: ubuntu-24.04
     timeout-minutes: 45
     strategy:
       fail-fast: false
       matrix:
+        python: [
+          { interpreter: 'python3.13', package: 'python3.13', compatibility: "manylinux_2_17" },
+        ]
         arch: [
           {
             cc: "clang",
             cflags: "-Os -fstrict-aliasing -fno-plt -flto=full -emit-llvm",
             features: "no-panic,unstable-simd,yyjson",
             ldflags: "-fuse-ld=lld -Wl,-plugin-opt=also-emit-llvm -Wl,--as-needed -Wl,-zrelro,-znow",
-            rustflags: "-C linker=clang -C link-arg=-fuse-ld=lld -C linker-plugin-lto -C lto=fat -C link-arg=-Wl,-zrelro,-znow -Z mir-opt-level=4 -Z virtual-function-elimination -Z threads=4 -D warnings",
+            rustflags: "-C linker=clang -C link-arg=-fuse-ld=lld -C linker-plugin-lto -C lto=fat -C link-arg=-Wl,-zrelro,-znow -Z mir-opt-level=4 -Z threads=4 -D warnings",
             tag: "aarch64",
             target: "aarch64-unknown-linux-gnu",
           },
         ]
-        python: [
-          { interpreter: 'python3.13', package: 'python3.13' },
-        ]
     env:
       PYTHON: "${{ matrix.python.interpreter }}"
       PYTHON_PACKAGE: "${{ matrix.python.package }}"
@@ -182,6 +183,7 @@ jobs:
       LDFLAGS: "${{ matrix.arch.ldflags }}"
       RUSTFLAGS: "${{ matrix.arch.rustflags }}"
       CARGO_TARGET_DIR: "/tmp/orjson"
+      COMPATIBILITY: "${{ matrix.python.compatibility }}"
     steps:
 
     - name: cpuinfo
@@ -212,18 +214,17 @@ jobs:
 
         ./script/install-fedora
 
-        source "${HOME}/.cargo/env"
         source "${VENV}/bin/activate"
 
         maturin build --release --strip \
           --features="${FEATURES}" \
-          --compatibility=manylinux_2_17 \
+          --compatibility="${COMPATIBILITY}" \
           --interpreter="${PYTHON}" \
           --target="${TARGET}"
 
         uv pip install ${CARGO_TARGET_DIR}/wheels/orjson*.whl
 
-        pytest -s -rxX -v -n 2 test
+        pytest -v test
 
         cp ${CARGO_TARGET_DIR}/wheels/orjson*.whl dist
 
@@ -231,12 +232,12 @@ jobs:
       if: "startsWith(github.ref, 'refs/tags/')"
       uses: actions/upload-artifact@v4
       with:
-        name: orjson_manylinux_2_17_aarch64_${{ matrix.python.interpreter }}
+        name: orjson_manylinux_aarch64_${{ matrix.python.interpreter }}
         path: dist
         overwrite: true
         retention-days: 1
 
-  musllinux_1_2:
+  musllinux:
     runs-on: ubuntu-24.04
     strategy:
       fail-fast: false
@@ -272,7 +273,7 @@ jobs:
         CC: "gcc"
         CFLAGS: "-Os"
         LDFLAGS: "-Wl,--as-needed"
-        RUSTFLAGS: "-C lto=fat -Z mir-opt-level=4 -Z virtual-function-elimination -Z threads=2 -D warnings -C target-feature=-crt-static"
+        RUSTFLAGS: "-C lto=fat -Z mir-opt-level=4 -Z threads=2 -D warnings -C target-feature=-crt-static"
       with:
         rust-toolchain: "${{ env.RUST_TOOLCHAIN }}"
         rustup-components: rust-src
@@ -301,18 +302,18 @@ jobs:
           venv/bin/pip install -U pip wheel
           venv/bin/pip install -r test/requirements.txt
           venv/bin/pip install orjson --no-index --find-links dist/ --force-reinstall
-          venv/bin/python -m pytest -s -rxX -v -n 2 test
+          venv/bin/python -m pytest -v test
 
     - name: Store wheels
       if: "startsWith(github.ref, 'refs/tags/')"
       uses: actions/upload-artifact@v4
       with:
-        name: orjson_musllinux_1_2_${{ matrix.platform.arch }}_${{ matrix.python.version }}
+        name: orjson_musllinux_${{ matrix.platform.arch }}_${{ matrix.python.version }}
         path: dist
         overwrite: true
         retention-days: 1
 
-  manylinux_2_17_non_amd64:
+  manylinux_non_amd64:
     runs-on: ubuntu-24.04
     strategy:
       fail-fast: false
@@ -385,7 +386,7 @@ jobs:
         overwrite: true
         retention-days: 1
 
-  macos_universal2_aarch64:
+  macos_aarch64:
     runs-on: macos-14
     strategy:
       fail-fast: false
@@ -402,7 +403,7 @@ jobs:
       LDFLAGS: "-Wl,--as-needed"
       CFLAGS_x86_64_apple_darwin: "-O2 -fstrict-aliasing -flto=full -march=x86-64-v2 -mtune=generic"
       CFLAGS_aarch64_apple_darwin: "-O2 -fstrict-aliasing -flto=full -mcpu=apple-m1 -mtune=generic"
-      RUSTFLAGS: "-C lto=fat -Z mir-opt-level=4 -Z virtual-function-elimination -Z threads=3 -D warnings"
+      RUSTFLAGS: "-C lto=fat -Z mir-opt-level=4 -Z threads=3 -D warnings"
       PATH: "/Users/runner/work/orjson/orjson/.venv/bin:/Users/runner/.cargo/bin:/usr/local/opt/curl/bin:/usr/local/bin:/usr/local/sbin:/Users/runner/bin:/Library/Frameworks/Python.framework/Versions/Current/bin:/usr/bin:/bin:/usr/sbin:/sbin"
     steps:
 
@@ -441,7 +442,7 @@ jobs:
           --target=universal2-apple-darwin
         uv pip install target/wheels/orjson*.whl
 
-    - run: pytest -s -rxX -v -n 3 test
+    - run: pytest -v test
       env:
         PYTHONMALLOC: "debug"
 
@@ -458,7 +459,7 @@ jobs:
         overwrite: true
         retention-days: 1
 
-  macos_universal2_amd64:
+  macos_amd64:
     runs-on: macos-13
     strategy:
       fail-fast: false
@@ -473,7 +474,7 @@ jobs:
       LDFLAGS: "-Wl,--as-needed"
       CFLAGS_x86_64_apple_darwin: "-O2 -fstrict-aliasing -flto=full -march=x86-64-v2 -mtune=generic"
       CFLAGS_aarch64_apple_darwin: "-O2 -fstrict-aliasing -flto=full -mcpu=apple-m1 -mtune=generic"
-      RUSTFLAGS: "-C lto=fat -Z mir-opt-level=4 -Z virtual-function-elimination -Z threads=3 -D warnings"
+      RUSTFLAGS: "-C lto=fat -Z mir-opt-level=4 -Z threads=3 -D warnings"
       PATH: "/Users/runner/work/orjson/orjson/.venv/bin:/Users/runner/.cargo/bin:/usr/local/opt/curl/bin:/usr/local/bin:/usr/local/sbin:/Users/runner/bin:/Library/Frameworks/Python.framework/Versions/Current/bin:/usr/bin:/bin:/usr/sbin:/sbin"
     steps:
 
@@ -511,7 +512,7 @@ jobs:
           --target=universal2-apple-darwin
         uv pip install target/wheels/orjson*.whl
 
-    - run: pytest -s -rxX -v -n 3 test
+    - run: pytest -v test
       env:
         PYTHONMALLOC: "debug"
 
@@ -533,29 +534,39 @@ jobs:
     runs-on: ubuntu-24.04
     if: "startsWith(github.ref, 'refs/tags/')"
     needs: [
-      macos_universal2_aarch64,
-      macos_universal2_amd64,
-      manylinux_2_17_aarch64,
-      manylinux_2_17_amd64,
-      manylinux_2_17_non_amd64,
-      musllinux_1_2,
+      macos_aarch64,
+      macos_amd64,
+      manylinux_aarch64,
+      manylinux_amd64,
+      manylinux_non_amd64,
+      musllinux,
       sdist,
     ]
+    environment:
+      name: pypi
+      url: https://pypi.org/p/orjson
+    permissions:
+      id-token: write
     steps:
       - uses: actions/download-artifact@v4
         with:
-          pattern: orjson_*
           merge-multiple: true
+          name: python-package-distributions
+          path: dist/
+          pattern: orjson_*
+
+      - run: ls -1 dist/
+
       - uses: actions/setup-python@v5
         with:
           python-version: "3.12"
-      - run: pip install pip "maturin>=1,<2"
-      - run: ls -1 .
-      - name: deploy wheel
-        run: maturin upload --skip-existing --username "$MATURIN_USERNAME" *.whl
-        env:
-          MATURIN_PYPI_TOKEN: ${{ secrets.PYPI_TOKEN }}
-      - name: deploy sdist
-        run: maturin upload --skip-existing --username "$MATURIN_USERNAME" *.tar.gz
-        env:
-          MATURIN_PYPI_TOKEN: ${{ secrets.PYPI_TOKEN }}
+
+      - name: Publish distribution to PyPI
+        uses: pypa/gh-action-pypi-publish@release/v1
+        with:
+          attestations: true
+          packages-dir: dist
+          repository-url: https://github.com/ijl/orjson
+          skip-existing: true
+          user: ijl
+          verbose: true
diff --git a/.github/workflows/debug.yaml b/.github/workflows/debug.yaml
index 60c9fe05..863135ac 100644
--- a/.github/workflows/debug.yaml
+++ b/.github/workflows/debug.yaml
@@ -10,8 +10,8 @@ jobs:
         profile: [
           { rust: "1.72", features: "" },
           { rust: "1.72", features: "--features=yyjson" },
-          { rust: "nightly-2024-09-25", features: "--features=yyjson,unstable-simd"},
-          { rust: "nightly-2024-09-25", features: "--features=avx512,yyjson,unstable-simd"},
+          { rust: "nightly-2024-09-25", features: "--features=yyjson,unstable-simd" },
+          { rust: "nightly-2024-09-25", features: "--features=avx512,yyjson,unstable-simd" },
         ]
         python: [
           { version: '3.13' },
@@ -27,12 +27,8 @@ jobs:
     steps:
     - run: curl https://sh.rustup.rs -sSf | sh -s -- --default-toolchain ${{ matrix.profile.rust }} --profile minimal -y
 
-    - name: cpuinfo
-      run: cat /proc/cpuinfo
-
     - uses: actions/setup-python@v5
       with:
-        allow-prereleases: true
         python-version: '${{ matrix.python.version }}'
 
     - run: python -m pip install --user --upgrade pip "maturin>=1,<2" wheel
diff --git a/.github/workflows/lint.yaml b/.github/workflows/lint.yaml
index df817411..e97ed4b5 100644
--- a/.github/workflows/lint.yaml
+++ b/.github/workflows/lint.yaml
@@ -8,7 +8,7 @@ jobs:
       with:
         python-version: "3.12"
     - run: curl https://sh.rustup.rs -sSf | sh -s -- --default-toolchain=stable --profile=default -y
-    - run: pip install -U autoflake isort black ruff mypy types-python-dateutil types-pytz types-simplejson types-ujson
+    - run: pip install -U ruff==0.7.1 mypy==1.13.0
 
     - uses: actions/checkout@v4
 
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 9688cd4c..f8a740e1 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,7 +1,7 @@
 # Changelog
 
 
-### 3.10.10
+## 3.10.10
 
 ### Fixed
 
@@ -12,7 +12,7 @@
 - Publish aarch64 manylinux_2_17 wheel for 3.13 to PyPI.
 
 
-### 3.10.9
+## 3.10.9
 
 ### Fixed
 
@@ -20,7 +20,7 @@
 introduced in 3.10.8.
 
 
-### 3.10.8
+## 3.10.8
 
 ### Changed
 
diff --git a/Cargo.lock b/Cargo.lock
index 029b5505..fc7f72bb 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -61,9 +61,9 @@ checksum = "7a81dae078cea95a014a339291cec439d2f232ebe854a9d672b796c6afafa9b7"
 
 [[package]]
 name = "encoding_rs"
-version = "0.8.34"
+version = "0.8.35"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b45de904aa0b010bce2ab45264d0631681847fa7b6f2eaa7dab7619943bc4f59"
+checksum = "75030f3c4f45dafd7586dd6780965a8c7e8e285a5ecb86713e63a79c5b2766f3"
 dependencies = [
  "cfg-if",
 ]
@@ -101,9 +101,9 @@ checksum = "9028f49264629065d057f340a86acb84867925865f73bbf8d47b4d149a7e88b8"
 
 [[package]]
 name = "jiff"
-version = "0.1.13"
+version = "0.1.14"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8a45489186a6123c128fdf6016183fcfab7113e1820eb813127e036e287233fb"
+checksum = "b9d9d414fc817d3e3d62b2598616733f76c4cc74fbac96069674739b881295c8"
 
 [[package]]
 name = "libc"
@@ -163,9 +163,9 @@ dependencies = [
 
 [[package]]
 name = "proc-macro2"
-version = "1.0.88"
+version = "1.0.89"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7c3a7fc5db1e57d5a779a352c8cdb57b29aa4c40cc69c3a68a7fedc815fbf2f9"
+checksum = "f139b0662de085916d1fb67d2b4169d1addddda1919e696f3252b740b629986e"
 dependencies = [
  "unicode-ident",
 ]
@@ -212,18 +212,18 @@ dependencies = [
 
 [[package]]
 name = "serde"
-version = "1.0.211"
+version = "1.0.214"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1ac55e59090389fb9f0dd9e0f3c09615afed1d19094284d0b200441f13550793"
+checksum = "f55c3193aca71c12ad7890f1785d2b73e1b9f63a0bbc353c08ef26fe03fc56b5"
 dependencies = [
  "serde_derive",
 ]
 
 [[package]]
 name = "serde_derive"
-version = "1.0.211"
+version = "1.0.214"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "54be4f245ce16bc58d57ef2716271d0d4519e0f6defa147f6e081005bcb278ff"
+checksum = "de523f781f095e28fa605cdce0f8307e451cc0fd14e2eb4cd2e98a355b147766"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -268,9 +268,9 @@ checksum = "a2eb9349b6444b326872e140eb1cf5e7c522154d69e7a0ffb0fb81c06b37543f"
 
 [[package]]
 name = "syn"
-version = "2.0.82"
+version = "2.0.86"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "83540f837a8afc019423a8edb95b52a8effe46957ee402287f4292fae35be021"
+checksum = "e89275301d38033efb81a6e60e3497e734dfcc62571f2854bf4b16690398824c"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -296,7 +296,6 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "dc55842d0db6329a669d55a623c674b02d677b16bfb2d24857d4089d41eba882"
 dependencies = [
  "gimli",
- "libc",
 ]
 
 [[package]]
diff --git a/Cargo.toml b/Cargo.toml
index 4a76eae4..365b0f3e 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -51,10 +51,10 @@ unwind = ["unwinding"]
 yyjson = []
 
 # Features detected by build.rs. Do not specify.
+inline_int = []
 intrinsics = []
 optimize = []
-strict_provenance = []
-inline_int = []
+setitem_knownhash = []
 
 [dependencies]
 associative-cache = { version = "2", default-features = false }
@@ -72,7 +72,7 @@ serde = { version = "1", default-features = false }
 serde_json = { version = "1", default-features = false, features = ["std", "float_roundtrip"] }
 simdutf8 = { version = "0.1", default-features = false, features = ["std", "public_imp", "aarch64_neon"] }
 smallvec = { version = "^1.11", default-features = false, features = ["union", "write"] }
-unwinding = { version = "=0.2.2", features = ["unwinder"], optional = true }
+unwinding = { version = "=0.2.2", default-features = false, features = ["unwinder"], optional = true }
 uuid = { version = "1", default-features = false }
 xxhash-rust = { version = "^0.8", default-features = false, features = ["xxh3"] }
 
diff --git a/README.md b/README.md
index 2fa365c7..942597ef 100644
--- a/README.md
+++ b/README.md
@@ -1202,6 +1202,14 @@ level above this.
 
 No. `bytes` is the correct type for a serialized blob.
 
+### Will it support NDJSON or JSONL?
+
+No. [orjsonl](https://github.com/umarbutler/orjsonl) may be appropriate.
+
+### Will it support JSON5 or RJSON?
+
+No, it supports RFC 8259.
+
 ## Packaging
 
 To package orjson requires at least [Rust](https://www.rust-lang.org/) 1.72
diff --git a/build.rs b/build.rs
index 4eac1746..3dfd2cc5 100644
--- a/build.rs
+++ b/build.rs
@@ -23,10 +23,15 @@ fn main() {
     println!("cargo:rustc-check-cfg=cfg(Py_3_9)");
     println!("cargo:rustc-check-cfg=cfg(Py_GIL_DISABLED)");
 
-    for cfg in pyo3_build_config::get().build_script_outputs() {
+    let python_config = pyo3_build_config::get();
+    for cfg in python_config.build_script_outputs() {
         println!("{cfg}");
     }
 
+    if python_config.version.minor != 13 {
+        println!("cargo:rustc-cfg=feature=\"setitem_knownhash\"");
+    }
+
     if let Some(true) = version_check::supports_feature("core_intrinsics") {
         println!("cargo:rustc-cfg=feature=\"intrinsics\"");
     }
@@ -35,10 +40,6 @@ fn main() {
         println!("cargo:rustc-cfg=feature=\"optimize\"");
     }
 
-    if let Some(true) = version_check::supports_feature("strict_provenance") {
-        println!("cargo:rustc-cfg=feature=\"strict_provenance\"");
-    }
-
     #[cfg(any(target_arch = "x86_64", target_arch = "aarch64"))]
     if env::var("ORJSON_DISABLE_SIMD").is_err() {
         // auto build unstable SIMD on nightly
diff --git a/ci/azure-win.yml b/ci/azure-win.yml
index 0424b536..655eab96 100644
--- a/ci/azure-win.yml
+++ b/ci/azure-win.yml
@@ -24,7 +24,7 @@ steps:
   env:
     CFLAGS: "-Os -flto"
     LDFLAGS: "-Wl,--as-needed"
-    RUSTFLAGS: "-C lto=fat -Z mir-opt-level=4 -Z virtual-function-elimination -D warnings"
+    RUSTFLAGS: "-C lto=fat -Z mir-opt-level=4 -D warnings"
     CARGO_UNSTABLE_SPARSE_REGISTRY: "true"
     UNSAFE_PYO3_SKIP_VERSION_CHECK: "1"
 - script: python.exe -m pip install orjson --no-index --find-links=D:\a\1\s\target\wheels
diff --git a/include/pyo3/pyo3-ffi/src/cpython/critical_section.rs b/include/pyo3/pyo3-ffi/src/cpython/critical_section.rs
index 97b2f5e0..884d9b92 100644
--- a/include/pyo3/pyo3-ffi/src/cpython/critical_section.rs
+++ b/include/pyo3/pyo3-ffi/src/cpython/critical_section.rs
@@ -9,6 +9,17 @@ pub struct PyCriticalSection {
     _cs_mutex: *mut PyMutex,
 }
 
+#[cfg(Py_GIL_DISABLED)]
+impl Default for PyCriticalSection {
+    fn default() -> Self {
+        let mut mutex = PyMutex::new();
+        PyCriticalSection {
+            _cs_prev: 0,
+            _cs_mutex: &mut mutex,
+        }
+    }
+}
+
 #[repr(C)]
 #[cfg(Py_GIL_DISABLED)]
 pub struct PyCriticalSection2 {
diff --git a/include/pyo3/pyo3-ffi/src/cpython/dictobject.rs b/include/pyo3/pyo3-ffi/src/cpython/dictobject.rs
index 79dcbfdb..0811326e 100644
--- a/include/pyo3/pyo3-ffi/src/cpython/dictobject.rs
+++ b/include/pyo3/pyo3-ffi/src/cpython/dictobject.rs
@@ -36,6 +36,15 @@ extern "C" {
         item: *mut PyObject,
         hash: crate::Py_hash_t,
     ) -> c_int;
+
+    #[cfg(Py_3_14)]
+    pub fn _PyDict_SetItem_KnownHash_LockHeld(
+        mp: *mut PyDictObject,
+        name: *mut PyObject,
+        value: *mut PyObject,
+        hash: crate::Py_hash_t,
+    ) -> c_int;
+
     // skipped _PyDict_DelItem_KnownHash
     // skipped _PyDict_DelItemIf
     // skipped _PyDict_NewKeysForClass
diff --git a/include/pyo3/pyo3-ffi/src/datetime.rs b/include/pyo3/pyo3-ffi/src/datetime.rs
index 7283b6d4..76d12151 100644
--- a/include/pyo3/pyo3-ffi/src/datetime.rs
+++ b/include/pyo3/pyo3-ffi/src/datetime.rs
@@ -4,16 +4,17 @@
 //! and covers the various date and time related objects in the Python `datetime`
 //! standard library module.
 
+#[cfg(not(PyPy))]
+use crate::PyCapsule_Import;
 #[cfg(GraalPy)]
 use crate::{PyLong_AsLong, PyLong_Check, PyObject_GetAttrString, Py_DecRef};
 use crate::{PyObject, PyObject_TypeCheck, PyTypeObject, Py_TYPE};
-use std::cell::UnsafeCell;
 #[cfg(not(GraalPy))]
 use std::os::raw::c_char;
 use std::os::raw::c_int;
 use std::ptr;
-#[cfg(not(PyPy))]
-use {crate::PyCapsule_Import, std::ffi::CString};
+use std::sync::Once;
+use std::{cell::UnsafeCell, ffi::CStr};
 #[cfg(not(any(PyPy, GraalPy)))]
 use {crate::Py_hash_t, std::os::raw::c_uchar};
 // Type struct wrappers
@@ -593,6 +594,8 @@ pub struct PyDateTime_CAPI {
 // Python already shares this object between threads, so it's no more evil for us to do it too!
 unsafe impl Sync for PyDateTime_CAPI {}
 
+pub const PyDateTime_CAPSULE_NAME: &CStr = c_str!("datetime.datetime_CAPI");
+
 /// Returns a pointer to a `PyDateTime_CAPI` instance
 ///
 /// # Note
@@ -600,33 +603,38 @@ unsafe impl Sync for PyDateTime_CAPI {}
 /// `PyDateTime_IMPORT` is called
 #[inline]
 pub unsafe fn PyDateTimeAPI() -> *mut PyDateTime_CAPI {
-    *PyDateTimeAPI_impl.0.get()
-}
-
-#[inline]
-pub unsafe fn PyDateTime_TimeZone_UTC() -> *mut PyObject {
-    (*PyDateTimeAPI()).TimeZone_UTC
+    *PyDateTimeAPI_impl.ptr.get()
 }
 
 /// Populates the `PyDateTimeAPI` object
 pub unsafe fn PyDateTime_IMPORT() {
-    // PyPy expects the C-API to be initialized via PyDateTime_Import, so trying to use
-    // `PyCapsule_Import` will behave unexpectedly in pypy.
-    #[cfg(PyPy)]
-    let py_datetime_c_api = PyDateTime_Import();
-
-    #[cfg(not(PyPy))]
-    let py_datetime_c_api = {
-        // PyDateTime_CAPSULE_NAME is a macro in C
-        let PyDateTime_CAPSULE_NAME = CString::new("datetime.datetime_CAPI").unwrap();
-
-        PyCapsule_Import(PyDateTime_CAPSULE_NAME.as_ptr(), 1) as *mut PyDateTime_CAPI
-    };
+    if !PyDateTimeAPI_impl.once.is_completed() {
+        // PyPy expects the C-API to be initialized via PyDateTime_Import, so trying to use
+        // `PyCapsule_Import` will behave unexpectedly in pypy.
+        #[cfg(PyPy)]
+        let py_datetime_c_api = PyDateTime_Import();
+
+        #[cfg(not(PyPy))]
+        let py_datetime_c_api =
+            PyCapsule_Import(PyDateTime_CAPSULE_NAME.as_ptr(), 1) as *mut PyDateTime_CAPI;
+
+        if py_datetime_c_api.is_null() {
+            return;
+        }
 
-    *PyDateTimeAPI_impl.0.get() = py_datetime_c_api;
+        // Protect against race conditions when the datetime API is concurrently
+        // initialized in multiple threads. UnsafeCell.get() cannot panic so this
+        // won't panic either.
+        PyDateTimeAPI_impl.once.call_once(|| {
+            *PyDateTimeAPI_impl.ptr.get() = py_datetime_c_api;
+        });
+    }
 }
 
-// skipped non-limited PyDateTime_TimeZone_UTC
+#[inline]
+pub unsafe fn PyDateTime_TimeZone_UTC() -> *mut PyObject {
+    (*PyDateTimeAPI()).TimeZone_UTC
+}
 
 /// Type Check macros
 ///
@@ -739,8 +747,13 @@ extern "C" {
 
 // Rust specific implementation details
 
-struct PyDateTimeAPISingleton(UnsafeCell<*mut PyDateTime_CAPI>);
+struct PyDateTimeAPISingleton {
+    once: Once,
+    ptr: UnsafeCell<*mut PyDateTime_CAPI>,
+}
 unsafe impl Sync for PyDateTimeAPISingleton {}
 
-static PyDateTimeAPI_impl: PyDateTimeAPISingleton =
-    PyDateTimeAPISingleton(UnsafeCell::new(ptr::null_mut()));
+static PyDateTimeAPI_impl: PyDateTimeAPISingleton = PyDateTimeAPISingleton {
+    once: Once::new(),
+    ptr: UnsafeCell::new(ptr::null_mut()),
+};
diff --git a/include/pyo3/pyo3-ffi/src/lib.rs b/include/pyo3/pyo3-ffi/src/lib.rs
index c6157401..293c5171 100644
--- a/include/pyo3/pyo3-ffi/src/lib.rs
+++ b/include/pyo3/pyo3-ffi/src/lib.rs
@@ -43,10 +43,39 @@
 //! PyO3 uses `rustc`'s `--cfg` flags to enable or disable code used for different Python versions.
 //! If you want to do this for your own crate, you can do so with the [`pyo3-build-config`] crate.
 //!
-//! - `Py_3_7`, `Py_3_8`, `Py_3_9`, `Py_3_10`: Marks code that is only enabled when
-//!  compiling for a given minimum Python version.
+//! - `Py_3_7`, `Py_3_8`, `Py_3_9`, `Py_3_10`, `Py_3_11`, `Py_3_12`, `Py_3_13`: Marks code that is
+//!    only enabled when compiling for a given minimum Python version.
 //! - `Py_LIMITED_API`: Marks code enabled when the `abi3` feature flag is enabled.
+//! - `Py_GIL_DISABLED`: Marks code that runs only in the free-threaded build of CPython.
 //! - `PyPy` - Marks code enabled when compiling for PyPy.
+//! - `GraalPy` - Marks code enabled when compiling for GraalPy.
+//!
+//! Additionally, you can query for the values `Py_DEBUG`, `Py_REF_DEBUG`,
+//! `Py_TRACE_REFS`, and `COUNT_ALLOCS` from `py_sys_config` to query for the
+//! corresponding C build-time defines. For example, to conditionally define
+//! debug code using `Py_DEBUG`, you could do:
+//!
+//! ```rust,ignore
+//! #[cfg(py_sys_config = "Py_DEBUG")]
+//! println!("only runs if python was compiled with Py_DEBUG")
+//! ```
+//!
+//! To use these attributes, add [`pyo3-build-config`] as a build dependency in
+//! your `Cargo.toml`:
+//!
+//! ```toml
+//! [build-dependency]
+//! pyo3-build-config = "VER"
+//! ```
+//!
+//! And then either create a new `build.rs` file in the project root or modify
+//! the existing `build.rs` file to call `use_pyo3_cfgs()`:
+//!
+//! ```rust,ignore
+//! fn main() {
+//!     pyo3_build_config::use_pyo3_cfgs();
+//! }
+//! ```
 //!
 //! # Minimum supported Rust and Python versions
 //!
diff --git a/pyproject.toml b/pyproject.toml
index 38ae9c19..f72f842c 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -25,6 +25,7 @@ classifiers = [
 ]
 
 [project.urls]
+Documentation = "https://github.com/ijl/orjson"
 Changelog = "https://github.com/ijl/orjson/blob/master/CHANGELOG.md"
 
 [build-system]
@@ -58,3 +59,7 @@ known-first-party = ["orjson"]
 
 [tool.mypy]
 python_version = "3.8"
+
+[[tool.mypy.overrides]]
+module = ["dateutil", "pytz", "simplejson", "ujson"]
+ignore_missing_imports = true
diff --git a/requirements.txt b/requirements.txt
index 27539a21..9981cc8c 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -2,9 +2,5 @@
 -r integration/requirements.txt
 -r test/requirements.txt
 maturin
-mypy==1.12.0
-ruff==0.7.0
-types-python-dateutil
-types-pytz
-types-simplejson
-types-ujson
+mypy==1.13.0
+ruff==0.7.1
diff --git a/script/develop b/script/develop
index fcab003b..b92a22e9 100755
--- a/script/develop
+++ b/script/develop
@@ -14,7 +14,9 @@ echo "CC: ${CC}, LD: ${LD}, LD_LIBRARY_PATH: ${LD_LIBRARY_PATH}"
 
 export CFLAGS="-Os -fstrict-aliasing -fno-plt -flto=full -emit-llvm"
 export LDFLAGS="-fuse-ld=${LD} -Wl,-plugin-opt=also-emit-llvm -Wl,--as-needed -Wl,-zrelro,-znow"
-export RUSTFLAGS="-C linker=${CC} -C link-arg=-fuse-ld=${LD} -C linker-plugin-lto -C lto=fat -C link-arg=-Wl,-zrelro,-znow -Z mir-opt-level=4 -Z virtual-function-elimination -Z threads=8"
+export RUSTFLAGS="-C linker=${CC} -C link-arg=-fuse-ld=${LD} -C linker-plugin-lto -C lto=fat -C link-arg=-Wl,-zrelro,-znow -Z mir-opt-level=4 -Z threads=8"
+
+rm -f ${CARGO_TARGET_DIR}/wheels/*.whl
 
 maturin build --target="${TARGET}" "$@"
 
diff --git a/script/pytest b/script/pytest
index 6b95014c..e8e7e51d 100755
--- a/script/pytest
+++ b/script/pytest
@@ -1,3 +1,3 @@
 #!/bin/sh -e
 
-PYTHONMALLOC="debug" pytest -s -rxX --random-order -n 4 test
+PYTHONMALLOC="debug" pytest -s test
diff --git a/src/lib.rs b/src/lib.rs
index 5fe295eb..64ace9e1 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -3,8 +3,6 @@
 #![cfg_attr(feature = "avx512", feature(stdarch_x86_avx512, avx512_target_feature))]
 #![cfg_attr(feature = "intrinsics", feature(core_intrinsics))]
 #![cfg_attr(feature = "optimize", feature(optimize_attribute))]
-#![cfg_attr(feature = "strict_provenance", feature(strict_provenance))]
-#![cfg_attr(feature = "strict_provenance", warn(fuzzy_provenance_casts))]
 #![cfg_attr(feature = "unstable-simd", feature(portable_simd))]
 #![allow(internal_features)] // core_intrinsics
 #![allow(non_camel_case_types)]
diff --git a/test/requirements.txt b/test/requirements.txt
index b07f7a6b..2c04102f 100644
--- a/test/requirements.txt
+++ b/test/requirements.txt
@@ -3,10 +3,8 @@ faker
 numpy;(platform_machine=="x86_64" or (platform_machine=="aarch64" and sys_platform == "linux")) and python_version<"3.13"
 pendulum;sys_platform=="linux" and platform_machine=="x86_64" and python_version<"3.12"
 time-machine < 2.15;sys_platform=="linux" and platform_machine=="x86_64" and python_version<"3.12"
-psutil;(sys_platform=="linux" or sys_platform == "macos") and platform_machine=="x86_64"
+psutil;(sys_platform=="linux" or sys_platform == "macos") and platform_machine=="x86_64" and python_version<"3.13"
 pytest
-pytest-random-order
-pytest-xdist
 pytz
 typing_extensions;python_version<"3.8"
 xxhash==1.4.3;sys_platform=="linux" and platform_machine=="x86_64" and python_version<"3.9" # creates non-compact ASCII for test_str_ascii