diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 2cf57011..0ef515c6 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -54,7 +54,7 @@ jobs:
     strategy:
       fail-fast: false  # If one platform fails, allow the rest to keep testing.
       matrix:
-        python-version: [3.6, 3.7, 3.8, 3.9, "3.10", pypy-3.6, pypy-3.7]
+        python-version: ["3.6", "3.7", "3.8", "3.9", "3.10", pypy-3.6, pypy-3.7]
         platform: [
           { os: "macos-latest",   python-architecture: "x64", rust-target: "x86_64-apple-darwin" },
           { os: "ubuntu-latest", python-architecture: "x64", rust-target: "x86_64-unknown-linux-gnu" },
@@ -96,10 +96,6 @@ jobs:
       - name: Install test dependencies
         run: pip install --upgrade tox nox setuptools
 
-      - name: Install wheel (workaround python 3.10 CI issue)
-        if: matrix.python-version == '3.10-dev'
-        run: pip install --upgrade wheel
-
       - name: Build package
         run: pip install -e .
 
@@ -110,7 +106,7 @@ jobs:
         run: nox -s test-examples
 
       - name: Test macOS universal2
-        if: matrix.platform.os == 'macos-latest' && !startsWith(matrix.python-version, 'pypy')
+        if: matrix.platform.os == 'macos-latest' && !startsWith(matrix.python-version, 'pypy') && matrix.python-version != '3.6'
         shell: bash
         env:
           DEVELOPER_DIR: /Applications/Xcode.app/Contents/Developer
@@ -128,6 +124,7 @@ jobs:
           python -c "from namespace_package import python; assert python.python_func() == 15"
 
       - name: Test sdist vendor Rust crates
+        if: matrix.python-version != '3.6' && matrix.python-version != 'pypy-3.6'
         shell: bash
         run: |
           cd examples/namespace_package
@@ -207,14 +204,14 @@ jobs:
           source ~/.cargo/env
           rustup target add ${{ matrix.platform.target }}
           cd examples/rust_with_cffi/
-          python3.6 -m pip install crossenv
-          python3.6 -m crossenv "/opt/python/cp36-cp36m/bin/python3" --cc $TARGET_CC --cxx $TARGET_CXX --sysroot $TARGET_SYSROOT --env LIBRARY_PATH= --manylinux manylinux1 venv
+          python3.9 -m pip install crossenv
+          python3.9 -m crossenv "/opt/python/cp39-cp39/bin/python3" --cc $TARGET_CC --cxx $TARGET_CXX --sysroot $TARGET_SYSROOT --env LIBRARY_PATH= --manylinux manylinux1 venv
           . venv/bin/activate
           build-pip install cffi wheel
           cross-expose cffi
           pip install wheel
           pip install -e ../../
-          python setup.py bdist_wheel --py-limited-api=cp36
+          python setup.py bdist_wheel --py-limited-api=cp37
           ls -la dist/
           ' > build-wheels.sh
 
@@ -258,14 +255,14 @@ jobs:
         env:
           CARGO: cross
           CARGO_BUILD_TARGET: aarch64-unknown-linux-gnu
-          PYO3_CROSS_LIB_DIR: /opt/python/cp38-cp38/lib
+          PYO3_CROSS_LIB_DIR: /opt/python/cp39-cp39/lib
         run: |
           cd examples/namespace_package
           docker build -t cross-pyo3:aarch64-unknown-linux-gnu .
           python -m pip install wheel
           python setup.py bdist_wheel --plat-name manylinux2014_aarch64
           ls -la dist/
-      - uses: uraimo/run-on-arch-action@v2.0.5
+      - uses: uraimo/run-on-arch-action@v2.1.1
         name: Install built wheel
         with:
           arch: aarch64
diff --git a/docs/building_wheels.md b/docs/building_wheels.md
index d4566b6d..8e7fbd8d 100644
--- a/docs/building_wheels.md
+++ b/docs/building_wheels.md
@@ -43,7 +43,6 @@ This will create wheels in the `dist` directory:
 
 ```bash
 $ ls dist
-hello_rust-0.1.0-cp36-cp36m-linux_x86_64.whl          hello_rust-0.1.0-cp36-cp36m-manylinux2014_x86_64.whl
 hello_rust-0.1.0-cp37-cp37m-linux_x86_64.whl          hello_rust-0.1.0-cp37-cp37m-manylinux2014_x86_64.whl
 hello_rust-0.1.0-cp38-cp38-linux_x86_64.whl           hello_rust-0.1.0-cp38-cp38-manylinux2014_x86_64.whl
 hello_rust-0.1.0-cp39-cp39-linux_x86_64.whl           hello_rust-0.1.0-cp39-cp39-manylinux2014_x86_64.whl
diff --git a/examples/html-py-ever/Cargo.lock b/examples/html-py-ever/Cargo.lock
index 51651839..cbef079d 100644
--- a/examples/html-py-ever/Cargo.lock
+++ b/examples/html-py-ever/Cargo.lock
@@ -4,21 +4,15 @@ version = 3
 
 [[package]]
 name = "bitflags"
-version = "1.2.1"
+version = "1.3.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "cf1de2fe8c75bc145a2f577add951f8134889b4795d47466a54a5c846d691693"
+checksum = "bef38d45163c2f1dde094a7dfd33ccf595c92905c8f8f4fdc18d06fb1037718a"
 
 [[package]]
 name = "byteorder"
-version = "1.3.4"
+version = "1.4.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "08c48aae112d48ed9f069b33538ea9e3e90aa263cfa3d1c24309612b1f7472de"
-
-[[package]]
-name = "cfg-if"
-version = "0.1.10"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4785bdd1c96b2a846b2bd7cc02e86b6b3dbf14e7e53446c4f54c92a361040822"
+checksum = "14c189c53d098945499cdfa7ecc63567cf3886b3332b312a5b4585d8d3a6a610"
 
 [[package]]
 name = "cfg-if"
@@ -27,13 +21,10 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
 
 [[package]]
-name = "cloudabi"
-version = "0.1.0"
+name = "convert_case"
+version = "0.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4344512281c643ae7638bbabc3af17a11307803ec8f0fcad9fae512a8bf36467"
-dependencies = [
- "bitflags",
-]
+checksum = "6245d59a3e82a7fc217c5828a6692dbc6dfb63a0c8c90495621f7b9d79704a0e"
 
 [[package]]
 name = "cssparser"
@@ -64,35 +55,37 @@ dependencies = [
 
 [[package]]
 name = "derive_more"
-version = "0.99.10"
+version = "0.99.17"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1dcfabdab475c16a93d669dddfc393027803e347d09663f524447f642fbb84ba"
+checksum = "4fb810d30a7c1953f91334de7244731fc3f3c10d7fe163338a35b9f640960321"
 dependencies = [
+ "convert_case",
  "proc-macro2",
  "quote",
+ "rustc_version",
  "syn",
 ]
 
 [[package]]
 name = "dtoa"
-version = "0.4.6"
+version = "0.4.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "134951f4028bdadb9b84baf4232681efbf277da25144b9b0ad65df75946c422b"
+checksum = "56899898ce76aaf4a0f24d914c97ea6ed976d42fec6ad33fcbb0a1103e07b2b0"
 
 [[package]]
 name = "dtoa-short"
-version = "0.3.2"
+version = "0.3.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "59020b8513b76630c49d918c33db9f4c91638e7d3404a28084083b87e33f76f2"
+checksum = "bde03329ae10e79ede66c9ce4dc930aa8599043b0743008548680f25b91502d6"
 dependencies = [
  "dtoa",
 ]
 
 [[package]]
 name = "futf"
-version = "0.1.4"
+version = "0.1.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7c9c1ce3fa9336301af935ab852c437817d14cd33690446569392e65170aac3b"
+checksum = "df420e2e84819663797d1ec6544b13c5be84629e7bb00dc960d6917db2987843"
 dependencies = [
  "mac",
  "new_debug_unreachable",
@@ -109,11 +102,11 @@ dependencies = [
 
 [[package]]
 name = "getrandom"
-version = "0.1.15"
+version = "0.1.16"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "fc587bc0ec293155d5bfa6b9891ec18a1e330c234f896ea47fbada4cadbe47e6"
+checksum = "8fc3cb4d91f53b50155bdcfd23f6a4c39ae1969c2ae85982b135750cccaf5fce"
 dependencies = [
- "cfg-if 0.1.10",
+ "cfg-if",
  "libc",
  "wasi",
 ]
@@ -143,38 +136,27 @@ dependencies = [
 
 [[package]]
 name = "indoc"
-version = "0.3.6"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "47741a8bc60fb26eb8d6e0238bbb26d8575ff623fdc97b1a2c00c050b9684ed8"
-dependencies = [
- "indoc-impl",
- "proc-macro-hack",
-]
-
-[[package]]
-name = "indoc-impl"
-version = "0.3.6"
+version = "1.0.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ce046d161f000fffde5f432a0d034d0341dc152643b2598ed5bfce44c4f3a8f0"
+checksum = "e7906a9fababaeacb774f72410e497a1d18de916322e33797bb2cd29baa23c9e"
 dependencies = [
- "proc-macro-hack",
- "proc-macro2",
- "quote",
- "syn",
  "unindent",
 ]
 
 [[package]]
 name = "instant"
-version = "0.1.6"
+version = "0.1.12"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5b141fdc7836c525d4d594027d318c84161ca17aaf8113ab1f81ab93ae897485"
+checksum = "7a5bbe824c507c5da5956355e86a746d82e0e1464f65d862cc5e71da70e94b2c"
+dependencies = [
+ "cfg-if",
+]
 
 [[package]]
 name = "itoa"
-version = "0.4.6"
+version = "0.4.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "dc6f3ad7b9d11a0c00842ff8de1b60ee58661048eb8049ed33c73594f359d7e6"
+checksum = "b71991ff56294aa922b450139ee08b3bfc70982c6b2c7562771375cf73542dd4"
 
 [[package]]
 name = "kuchiki"
@@ -196,26 +178,26 @@ checksum = "e2abad23fbc42b3700f2f279844dc832adb2b2eb069b2df918f455c4e18cc646"
 
 [[package]]
 name = "libc"
-version = "0.2.77"
+version = "0.2.119"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f2f96b10ec2560088a8e76961b00d47107b3a625fecb76dedb29ee7ccbf98235"
+checksum = "1bf2e165bb3457c8e098ea76f3e3bc9db55f87aa90d52d0e6be741470916aaa4"
 
 [[package]]
 name = "lock_api"
-version = "0.4.1"
+version = "0.4.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "28247cc5a5be2f05fbcd76dd0cf2c7d3b5400cb978a28042abcd4fa0b3f8261c"
+checksum = "88943dd7ef4a2e5a4bfa2753aaab3013e34ce2533d1996fb18ef591e315e2b3b"
 dependencies = [
  "scopeguard",
 ]
 
 [[package]]
 name = "log"
-version = "0.4.11"
+version = "0.4.14"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4fabed175da42fed1fa0746b0ea71f412aa9d35e76e95e59b192c64b9dc2bf8b"
+checksum = "51b9bbe6c47d51fc3e1a9b945965946b4c44142ab8792c50835a980d362c2710"
 dependencies = [
- "cfg-if 0.1.10",
+ "cfg-if",
 ]
 
 [[package]]
@@ -226,16 +208,13 @@ checksum = "c41e0c4fef86961ac6d6f8a82609f55f31b05e4fce149ac5710e439df7619ba4"
 
 [[package]]
 name = "markup5ever"
-version = "0.10.0"
+version = "0.10.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "aae38d669396ca9b707bfc3db254bc382ddb94f57cc5c235f34623a669a01dab"
+checksum = "a24f40fb03852d1cdd84330cddcaf98e9ec08a7b7768e952fad3b4cf048ec8fd"
 dependencies = [
  "log",
  "phf",
  "phf_codegen",
- "serde",
- "serde_derive",
- "serde_json",
  "string_cache",
  "string_cache_codegen",
  "tendril",
@@ -243,9 +222,9 @@ dependencies = [
 
 [[package]]
 name = "matches"
-version = "0.1.8"
+version = "0.1.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7ffc5c5338469d4d3ea17d269fa8ea3512ad247247c30bd2df69e68309ed0a08"
+checksum = "a3e378b66a060d48947b590737b30a1be76706c8dd7b8ba0f2fe3989c68a853f"
 
 [[package]]
 name = "new_debug_unreachable"
@@ -261,15 +240,15 @@ checksum = "72ef4a56884ca558e5ddb05a1d1e7e1bfd9a68d9ed024c21704cc98872dae1bb"
 
 [[package]]
 name = "once_cell"
-version = "1.8.0"
+version = "1.10.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "692fcb63b64b1758029e0a96ee63e049ce8c5948587f2f7208df04625e5f6b56"
+checksum = "87f3e037eac156d1775da914196f0f37741a274155e34a0b7e427c35d2a2ecb9"
 
 [[package]]
 name = "parking_lot"
-version = "0.11.0"
+version = "0.11.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a4893845fa2ca272e647da5d0e46660a314ead9c2fdd9a883aabc32e481a8733"
+checksum = "7d17b78036a60663b797adeaee46f5c9dfebb86948d1255007a1d6be0271ff99"
 dependencies = [
  "instant",
  "lock_api",
@@ -278,12 +257,11 @@ dependencies = [
 
 [[package]]
 name = "parking_lot_core"
-version = "0.8.0"
+version = "0.8.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c361aa727dd08437f2f1447be8b59a33b0edd15e0fcee698f935613d9efbca9b"
+checksum = "d76e8e1493bcac0d2766c42737f34458f1c8c50c0d23bcb24ea953affb273216"
 dependencies = [
- "cfg-if 0.1.10",
- "cloudabi",
+ "cfg-if",
  "instant",
  "libc",
  "redox_syscall",
@@ -291,25 +269,6 @@ dependencies = [
  "winapi",
 ]
 
-[[package]]
-name = "paste"
-version = "0.1.18"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "45ca20c77d80be666aef2b45486da86238fabe33e38306bd3118fe4af33fa880"
-dependencies = [
- "paste-impl",
- "proc-macro-hack",
-]
-
-[[package]]
-name = "paste-impl"
-version = "0.1.18"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d95a7db200b97ef370c8e6de0088252f7e0dfff7d047a28528e47456c0fc98b6"
-dependencies = [
- "proc-macro-hack",
-]
-
 [[package]]
 name = "phf"
 version = "0.8.0"
@@ -317,7 +276,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "3dfb61232e34fcb633f43d12c58f83c1df82962dcdfa565a4e866ffc17dafe12"
 dependencies = [
  "phf_macros",
- "phf_shared",
+ "phf_shared 0.8.0",
  "proc-macro-hack",
 ]
 
@@ -328,7 +287,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "cbffee61585b0411840d3ece935cce9cb6321f01c45477d30066498cd5e1a815"
 dependencies = [
  "phf_generator",
- "phf_shared",
+ "phf_shared 0.8.0",
 ]
 
 [[package]]
@@ -337,7 +296,7 @@ version = "0.8.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "17367f0cc86f2d25802b2c26ee58a7b23faeccf78a396094c13dced0d0182526"
 dependencies = [
- "phf_shared",
+ "phf_shared 0.8.0",
  "rand",
 ]
 
@@ -348,7 +307,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7f6fde18ff429ffc8fe78e2bf7f8b7a5a5a6e2a8b58bc5a9ac69198bbda9189c"
 dependencies = [
  "phf_generator",
- "phf_shared",
+ "phf_shared 0.8.0",
  "proc-macro-hack",
  "proc-macro2",
  "quote",
@@ -364,11 +323,20 @@ dependencies = [
  "siphasher",
 ]
 
+[[package]]
+name = "phf_shared"
+version = "0.10.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b6796ad771acdc0123d2a88dc428b5e38ef24456743ddb1744ed628f9815c096"
+dependencies = [
+ "siphasher",
+]
+
 [[package]]
 name = "ppv-lite86"
-version = "0.2.9"
+version = "0.2.16"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c36fa947111f5c62a733b652544dd0016a43ce89619538a8ef92724a6f501a20"
+checksum = "eb9f9e6e233e5c4a35559a617bf40a4ec447db2e84c20b55a6f83167b7e57872"
 
 [[package]]
 name = "precomputed-hash"
@@ -378,50 +346,61 @@ checksum = "925383efa346730478fb4838dbe9137d2a47675ad789c546d150a6e1dd4ab31c"
 
 [[package]]
 name = "proc-macro-hack"
-version = "0.5.18"
+version = "0.5.19"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "99c605b9a0adc77b7211c6b1f722dcb613d68d66859a44f3d485a6da332b0598"
+checksum = "dbf0c48bc1d91375ae5c3cd81e3722dff1abcf81a30960240640d223f59fe0e5"
 
 [[package]]
 name = "proc-macro2"
-version = "1.0.21"
+version = "1.0.36"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "36e28516df94f3dd551a587da5357459d9b36d945a7c37c3557928c1c2ff2a2c"
+checksum = "c7342d5883fbccae1cc37a2353b09c87c9b0f3afd73f5fb9bba687a1f733b029"
 dependencies = [
  "unicode-xid",
 ]
 
 [[package]]
 name = "pyo3"
-version = "0.15.1"
+version = "0.16.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7cf01dbf1c05af0a14c7779ed6f3aa9deac9c3419606ac9de537a2d649005720"
+checksum = "c00e5e97bb258ac0fcea67da5e845aae5f7e6fb4f723ec94a503a6d0a541ccb7"
 dependencies = [
- "cfg-if 1.0.0",
+ "cfg-if",
  "indoc",
  "libc",
  "parking_lot",
- "paste",
  "pyo3-build-config",
+ "pyo3-ffi",
  "pyo3-macros",
  "unindent",
 ]
 
 [[package]]
 name = "pyo3-build-config"
-version = "0.15.1"
+version = "0.16.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "dbf9e4d128bfbddc898ad3409900080d8d5095c379632fbbfbb9c8cfb1fb852b"
+checksum = "f61cb87bf5c9503fa0e7f38bcd311b31993328a5e29f3507dfbf763c8ccd37f4"
 dependencies = [
  "once_cell",
 ]
 
+[[package]]
+name = "pyo3-ffi"
+version = "0.16.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5dd4b0b76ae07ca5a7b0527a75afc9f47744d14f4f3576bdf66a9a2420b5c54d"
+dependencies = [
+ "libc",
+ "pyo3-build-config",
+]
+
 [[package]]
 name = "pyo3-macros"
-version = "0.15.1"
+version = "0.16.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "67701eb32b1f9a9722b4bc54b548ff9d7ebfded011c12daece7b9063be1fd755"
+checksum = "a845f73eda2aa27d35b3840e2c6f0c9447347cdb49954552f09ae7b1f432a3d9"
 dependencies = [
+ "proc-macro2",
  "pyo3-macros-backend",
  "quote",
  "syn",
@@ -429,9 +408,9 @@ dependencies = [
 
 [[package]]
 name = "pyo3-macros-backend"
-version = "0.15.1"
+version = "0.16.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f44f09e825ee49a105f2c7b23ebee50886a9aee0746f4dd5a704138a64b0218a"
+checksum = "4e72ef79ca96c2dcb66d9b22f149400ac6c6b32ab468398ebbcb145d72f80c00"
 dependencies = [
  "proc-macro2",
  "pyo3-build-config",
@@ -441,9 +420,9 @@ dependencies = [
 
 [[package]]
 name = "quote"
-version = "1.0.7"
+version = "1.0.15"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "aa563d17ecb180e500da1cfd2b028310ac758de548efdd203e18f283af693f37"
+checksum = "864d3e96a899863136fc6e99f3d7cae289dafe43bf2c5ac19b70df7210c0a145"
 dependencies = [
  "proc-macro2",
 ]
@@ -501,15 +480,21 @@ dependencies = [
 
 [[package]]
 name = "redox_syscall"
-version = "0.1.57"
+version = "0.2.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "41cc0f7e4d5d4544e8861606a285bb08d3e70712ccc7d2b84d7c0ccfaf4b05ce"
+checksum = "8380fe0152551244f0747b1bf41737e0f8a74f97a14ccefd1148187271634f3c"
+dependencies = [
+ "bitflags",
+]
 
 [[package]]
-name = "ryu"
-version = "1.0.5"
+name = "rustc_version"
+version = "0.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "71d301d4193d031abdd79ff7e3dd721168a9572ef3fe51a1517aba235bd8f86e"
+checksum = "bfa0f585226d2e68097d4f95d113b15b83a82e819ab25717ec0590d9584ef366"
+dependencies = [
+ "semver",
+]
 
 [[package]]
 name = "scopeguard"
@@ -538,32 +523,16 @@ dependencies = [
 ]
 
 [[package]]
-name = "serde"
-version = "1.0.116"
+name = "semver"
+version = "1.0.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "96fe57af81d28386a513cbc6858332abc6117cfdb5999647c6444b8f43a370a5"
+checksum = "a4a3381e03edd24287172047536f20cabde766e2cd3e65e6b00fb3af51c4f38d"
 
 [[package]]
-name = "serde_derive"
-version = "1.0.116"
+name = "serde"
+version = "1.0.136"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f630a6370fd8e457873b4bd2ffdae75408bc291ba72be773772a4c2a065d9ae8"
-dependencies = [
- "proc-macro2",
- "quote",
- "syn",
-]
-
-[[package]]
-name = "serde_json"
-version = "1.0.57"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "164eacbdb13512ec2745fb09d51fd5b22b0d65ed294a1dcf7285a360c80a675c"
-dependencies = [
- "itoa",
- "ryu",
- "serde",
-]
+checksum = "ce31e24b01e1e524df96f1c2fdd054405f8d7376249a5110886fb4b658484789"
 
 [[package]]
 name = "servo_arc"
@@ -577,15 +546,15 @@ dependencies = [
 
 [[package]]
 name = "siphasher"
-version = "0.3.3"
+version = "0.3.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "fa8f3741c7372e75519bd9346068370c9cdaabcc1f9599cbcf2a2719352286b7"
+checksum = "a86232ab60fa71287d7f2ddae4a7073f6b7aac33631c3015abb556f08c6d0a3e"
 
 [[package]]
 name = "smallvec"
-version = "1.4.2"
+version = "1.8.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "fbee7696b84bbf3d89a1c2eccff0850e3047ed46bfcd2e92c29a2d074d57e252"
+checksum = "f2dd574626839106c320a323308629dcb1acfc96e32a8cba364ddc61ac23ee83"
 
 [[package]]
 name = "stable_deref_trait"
@@ -595,13 +564,14 @@ checksum = "a8f112729512f8e442d81f95a8a7ddf2b7c6b8a1a6f509a95864142b30cab2d3"
 
 [[package]]
 name = "string_cache"
-version = "0.8.0"
+version = "0.8.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2940c75beb4e3bf3a494cef919a747a2cb81e52571e212bfbd185074add7208a"
+checksum = "33994d0838dc2d152d17a62adf608a869b5e846b65b389af7f3dbc1de45c5b26"
 dependencies = [
  "lazy_static",
  "new_debug_unreachable",
- "phf_shared",
+ "parking_lot",
+ "phf_shared 0.10.0",
  "precomputed-hash",
  "serde",
 ]
@@ -613,16 +583,16 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f24c8e5e19d22a726626f1a5e16fe15b132dcf21d10177fa5a45ce7962996b97"
 dependencies = [
  "phf_generator",
- "phf_shared",
+ "phf_shared 0.8.0",
  "proc-macro2",
  "quote",
 ]
 
 [[package]]
 name = "syn"
-version = "1.0.41"
+version = "1.0.86"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6690e3e9f692504b941dc6c3b188fd28df054f7fb8469ab40680df52fdcc842b"
+checksum = "8a65b3f4ffa0092e9887669db0eae07941f023991ab58ea44da8fe8e2d511c6b"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -648,21 +618,21 @@ checksum = "8eaa81235c7058867fa8c0e7314f33dcce9c215f535d1913822a2b3f5e289f3c"
 
 [[package]]
 name = "unicode-xid"
-version = "0.2.1"
+version = "0.2.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f7fe0bb3479651439c9112f72b6c505038574c9fbb575ed1bf3b797fa39dd564"
+checksum = "8ccb82d61f80a663efe1f787a51b16b5a51e3314d6ac365b08639f52387b33f3"
 
 [[package]]
 name = "unindent"
-version = "0.1.6"
+version = "0.1.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "af41d708427f8fd0e915dcebb2cae0f0e6acb2a939b2d399c265c39a38a18942"
+checksum = "514672a55d7380da379785a4d70ca8386c8883ff7eaae877be4d2081cebe73d8"
 
 [[package]]
 name = "utf-8"
-version = "0.7.5"
+version = "0.7.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "05e42f7c18b8f902290b009cde6d651262f956c98bc51bca4cd1d511c9cd85c7"
+checksum = "09cc8ee72d2a9becf2f2febe0205bbed8fc6615b7cb429ad062dc7b7ddd036a9"
 
 [[package]]
 name = "wasi"
diff --git a/examples/html-py-ever/Cargo.toml b/examples/html-py-ever/Cargo.toml
index 4e5b95bf..99b6c01b 100644
--- a/examples/html-py-ever/Cargo.toml
+++ b/examples/html-py-ever/Cargo.toml
@@ -6,7 +6,7 @@ edition = "2018"
 
 [dependencies]
 kuchiki = "0.8.0"
-pyo3 = { version = "0.15.1", features = ["extension-module"] }
+pyo3 = { version = "0.16.1", features = ["extension-module"] }
 tendril = "0.4.2"
 
 [lib]
diff --git a/examples/html-py-ever/build-wheels.sh b/examples/html-py-ever/build-wheels.sh
index b06c4db0..298698cd 100755
--- a/examples/html-py-ever/build-wheels.sh
+++ b/examples/html-py-ever/build-wheels.sh
@@ -12,7 +12,7 @@ for PYBIN in /opt/python/cp{36,37,38,39,310}*/bin; do
 done
 
 # Bundle external shared libraries into the wheels
-for whl in /io/dist/*{cp36,cp37,cp38,cp39,cp310}*.whl; do
+for whl in /io/dist/*{cp37,cp38,cp39,cp310}*.whl; do
     auditwheel repair "$whl" -w /io/dist/
 done
 
diff --git a/examples/html-py-ever/noxfile.py b/examples/html-py-ever/noxfile.py
index 9d09f8e0..740ff650 100644
--- a/examples/html-py-ever/noxfile.py
+++ b/examples/html-py-ever/noxfile.py
@@ -1,3 +1,4 @@
+import sys
 from os.path import dirname
 
 import nox
@@ -7,6 +8,7 @@
 
 @nox.session()
 def test(session: nox.Session):
-    session.install(SETUPTOOLS_RUST, "pytest", "pytest-benchmark", "beautifulsoup4")
-    session.install(".")
-    session.run("pytest", *session.posargs)
+    if sys.version_info >= (3, 7):
+        session.install(SETUPTOOLS_RUST, "pytest", "pytest-benchmark", "beautifulsoup4")
+        session.install(".")
+        session.run("pytest", *session.posargs)
diff --git a/examples/namespace_package/Cargo.lock b/examples/namespace_package/Cargo.lock
index f0487e96..1bcfb00f 100644
--- a/examples/namespace_package/Cargo.lock
+++ b/examples/namespace_package/Cargo.lock
@@ -96,9 +96,9 @@ dependencies = [
 
 [[package]]
 name = "pyo3"
-version = "0.16.0"
+version = "0.16.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9d1a3df45cb95bd954fac00bd9609062640fd7fb9e9946a660092c9e015421fb"
+checksum = "c00e5e97bb258ac0fcea67da5e845aae5f7e6fb4f723ec94a503a6d0a541ccb7"
 dependencies = [
  "cfg-if",
  "indoc",
@@ -112,18 +112,18 @@ dependencies = [
 
 [[package]]
 name = "pyo3-build-config"
-version = "0.16.0"
+version = "0.16.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "386a68f0f5f2f9932815068bc8049a56989f2437d96dbb31d1fb11b63ce90364"
+checksum = "f61cb87bf5c9503fa0e7f38bcd311b31993328a5e29f3507dfbf763c8ccd37f4"
 dependencies = [
  "once_cell",
 ]
 
 [[package]]
 name = "pyo3-ffi"
-version = "0.16.0"
+version = "0.16.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a9a4e2f74dc77eea5ce11d19f0afaeb632b6590f8cbb1d5ee2f1330b766803e8"
+checksum = "5dd4b0b76ae07ca5a7b0527a75afc9f47744d14f4f3576bdf66a9a2420b5c54d"
 dependencies = [
  "libc",
  "pyo3-build-config",
@@ -131,9 +131,9 @@ dependencies = [
 
 [[package]]
 name = "pyo3-macros"
-version = "0.16.0"
+version = "0.16.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "dbff3a1579934968a53bcc78ac33663ed2577accda05d484097679cc8d28e52d"
+checksum = "a845f73eda2aa27d35b3840e2c6f0c9447347cdb49954552f09ae7b1f432a3d9"
 dependencies = [
  "proc-macro2",
  "pyo3-macros-backend",
@@ -143,9 +143,9 @@ dependencies = [
 
 [[package]]
 name = "pyo3-macros-backend"
-version = "0.16.0"
+version = "0.16.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "90644126c8c1ac7b47f794dd20a5729f8646b91c49edb31689c90f8cb3c33ea9"
+checksum = "4e72ef79ca96c2dcb66d9b22f149400ac6c6b32ab468398ebbcb145d72f80c00"
 dependencies = [
  "proc-macro2",
  "pyo3-build-config",
diff --git a/examples/namespace_package/Cargo.toml b/examples/namespace_package/Cargo.toml
index 59deba41..1f37e2c8 100644
--- a/examples/namespace_package/Cargo.toml
+++ b/examples/namespace_package/Cargo.toml
@@ -7,4 +7,4 @@ edition = "2018"
 crate-type = ["cdylib"]
 
 [dependencies]
-pyo3 = { version = "0.16.0", features = ["extension-module"] }
+pyo3 = { version = "0.16.1", features = ["extension-module"] }
diff --git a/examples/namespace_package/Dockerfile b/examples/namespace_package/Dockerfile
index 0ecd9571..c07e20d3 100644
--- a/examples/namespace_package/Dockerfile
+++ b/examples/namespace_package/Dockerfile
@@ -5,9 +5,9 @@ FROM rustembedded/cross:aarch64-unknown-linux-gnu
 RUN apt-get update && \
     apt-get install -y software-properties-common && \
     add-apt-repository ppa:deadsnakes/ppa && \
-    apt-get update && \
-    apt-get install -y python3.8 && \
-    update-alternatives --install /usr/bin/python3 python3 /usr/bin/python3.8 1
+    apt-get update
+
+RUN python --version
 
 COPY --from=manylinux /opt/_internal /opt/_internal
 COPY --from=manylinux /opt/python /opt/python
diff --git a/examples/rust_with_cffi/Cargo.lock b/examples/rust_with_cffi/Cargo.lock
index cac5c5a3..860ac9aa 100644
--- a/examples/rust_with_cffi/Cargo.lock
+++ b/examples/rust_with_cffi/Cargo.lock
@@ -4,15 +4,9 @@ version = 3
 
 [[package]]
 name = "bitflags"
-version = "1.2.1"
+version = "1.3.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "cf1de2fe8c75bc145a2f577add951f8134889b4795d47466a54a5c846d691693"
-
-[[package]]
-name = "cfg-if"
-version = "0.1.10"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4785bdd1c96b2a846b2bd7cc02e86b6b3dbf14e7e53446c4f54c92a361040822"
+checksum = "bef38d45163c2f1dde094a7dfd33ccf595c92905c8f8f4fdc18d06fb1037718a"
 
 [[package]]
 name = "cfg-if"
@@ -20,70 +14,50 @@ version = "1.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
 
-[[package]]
-name = "cloudabi"
-version = "0.1.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4344512281c643ae7638bbabc3af17a11307803ec8f0fcad9fae512a8bf36467"
-dependencies = [
- "bitflags",
-]
-
 [[package]]
 name = "indoc"
-version = "0.3.6"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "47741a8bc60fb26eb8d6e0238bbb26d8575ff623fdc97b1a2c00c050b9684ed8"
-dependencies = [
- "indoc-impl",
- "proc-macro-hack",
-]
-
-[[package]]
-name = "indoc-impl"
-version = "0.3.6"
+version = "1.0.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ce046d161f000fffde5f432a0d034d0341dc152643b2598ed5bfce44c4f3a8f0"
+checksum = "e7906a9fababaeacb774f72410e497a1d18de916322e33797bb2cd29baa23c9e"
 dependencies = [
- "proc-macro-hack",
- "proc-macro2",
- "quote",
- "syn",
  "unindent",
 ]
 
 [[package]]
 name = "instant"
-version = "0.1.6"
+version = "0.1.12"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5b141fdc7836c525d4d594027d318c84161ca17aaf8113ab1f81ab93ae897485"
+checksum = "7a5bbe824c507c5da5956355e86a746d82e0e1464f65d862cc5e71da70e94b2c"
+dependencies = [
+ "cfg-if",
+]
 
 [[package]]
 name = "libc"
-version = "0.2.77"
+version = "0.2.119"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f2f96b10ec2560088a8e76961b00d47107b3a625fecb76dedb29ee7ccbf98235"
+checksum = "1bf2e165bb3457c8e098ea76f3e3bc9db55f87aa90d52d0e6be741470916aaa4"
 
 [[package]]
 name = "lock_api"
-version = "0.4.1"
+version = "0.4.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "28247cc5a5be2f05fbcd76dd0cf2c7d3b5400cb978a28042abcd4fa0b3f8261c"
+checksum = "88943dd7ef4a2e5a4bfa2753aaab3013e34ce2533d1996fb18ef591e315e2b3b"
 dependencies = [
  "scopeguard",
 ]
 
 [[package]]
 name = "once_cell"
-version = "1.8.0"
+version = "1.10.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "692fcb63b64b1758029e0a96ee63e049ce8c5948587f2f7208df04625e5f6b56"
+checksum = "87f3e037eac156d1775da914196f0f37741a274155e34a0b7e427c35d2a2ecb9"
 
 [[package]]
 name = "parking_lot"
-version = "0.11.0"
+version = "0.11.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a4893845fa2ca272e647da5d0e46660a314ead9c2fdd9a883aabc32e481a8733"
+checksum = "7d17b78036a60663b797adeaee46f5c9dfebb86948d1255007a1d6be0271ff99"
 dependencies = [
  "instant",
  "lock_api",
@@ -92,12 +66,11 @@ dependencies = [
 
 [[package]]
 name = "parking_lot_core"
-version = "0.8.0"
+version = "0.8.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c361aa727dd08437f2f1447be8b59a33b0edd15e0fcee698f935613d9efbca9b"
+checksum = "d76e8e1493bcac0d2766c42737f34458f1c8c50c0d23bcb24ea953affb273216"
 dependencies = [
- "cfg-if 0.1.10",
- "cloudabi",
+ "cfg-if",
  "instant",
  "libc",
  "redox_syscall",
@@ -105,71 +78,57 @@ dependencies = [
  "winapi",
 ]
 
-[[package]]
-name = "paste"
-version = "0.1.18"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "45ca20c77d80be666aef2b45486da86238fabe33e38306bd3118fe4af33fa880"
-dependencies = [
- "paste-impl",
- "proc-macro-hack",
-]
-
-[[package]]
-name = "paste-impl"
-version = "0.1.18"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d95a7db200b97ef370c8e6de0088252f7e0dfff7d047a28528e47456c0fc98b6"
-dependencies = [
- "proc-macro-hack",
-]
-
-[[package]]
-name = "proc-macro-hack"
-version = "0.5.18"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "99c605b9a0adc77b7211c6b1f722dcb613d68d66859a44f3d485a6da332b0598"
-
 [[package]]
 name = "proc-macro2"
-version = "1.0.21"
+version = "1.0.36"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "36e28516df94f3dd551a587da5357459d9b36d945a7c37c3557928c1c2ff2a2c"
+checksum = "c7342d5883fbccae1cc37a2353b09c87c9b0f3afd73f5fb9bba687a1f733b029"
 dependencies = [
  "unicode-xid",
 ]
 
 [[package]]
 name = "pyo3"
-version = "0.15.1"
+version = "0.16.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7cf01dbf1c05af0a14c7779ed6f3aa9deac9c3419606ac9de537a2d649005720"
+checksum = "c00e5e97bb258ac0fcea67da5e845aae5f7e6fb4f723ec94a503a6d0a541ccb7"
 dependencies = [
- "cfg-if 1.0.0",
+ "cfg-if",
  "indoc",
  "libc",
  "parking_lot",
- "paste",
  "pyo3-build-config",
+ "pyo3-ffi",
  "pyo3-macros",
  "unindent",
 ]
 
 [[package]]
 name = "pyo3-build-config"
-version = "0.15.1"
+version = "0.16.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "dbf9e4d128bfbddc898ad3409900080d8d5095c379632fbbfbb9c8cfb1fb852b"
+checksum = "f61cb87bf5c9503fa0e7f38bcd311b31993328a5e29f3507dfbf763c8ccd37f4"
 dependencies = [
  "once_cell",
 ]
 
+[[package]]
+name = "pyo3-ffi"
+version = "0.16.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5dd4b0b76ae07ca5a7b0527a75afc9f47744d14f4f3576bdf66a9a2420b5c54d"
+dependencies = [
+ "libc",
+ "pyo3-build-config",
+]
+
 [[package]]
 name = "pyo3-macros"
-version = "0.15.1"
+version = "0.16.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "67701eb32b1f9a9722b4bc54b548ff9d7ebfded011c12daece7b9063be1fd755"
+checksum = "a845f73eda2aa27d35b3840e2c6f0c9447347cdb49954552f09ae7b1f432a3d9"
 dependencies = [
+ "proc-macro2",
  "pyo3-macros-backend",
  "quote",
  "syn",
@@ -177,9 +136,9 @@ dependencies = [
 
 [[package]]
 name = "pyo3-macros-backend"
-version = "0.15.1"
+version = "0.16.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f44f09e825ee49a105f2c7b23ebee50886a9aee0746f4dd5a704138a64b0218a"
+checksum = "4e72ef79ca96c2dcb66d9b22f149400ac6c6b32ab468398ebbcb145d72f80c00"
 dependencies = [
  "proc-macro2",
  "pyo3-build-config",
@@ -189,18 +148,21 @@ dependencies = [
 
 [[package]]
 name = "quote"
-version = "1.0.7"
+version = "1.0.15"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "aa563d17ecb180e500da1cfd2b028310ac758de548efdd203e18f283af693f37"
+checksum = "864d3e96a899863136fc6e99f3d7cae289dafe43bf2c5ac19b70df7210c0a145"
 dependencies = [
  "proc-macro2",
 ]
 
 [[package]]
 name = "redox_syscall"
-version = "0.1.57"
+version = "0.2.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "41cc0f7e4d5d4544e8861606a285bb08d3e70712ccc7d2b84d7c0ccfaf4b05ce"
+checksum = "8380fe0152551244f0747b1bf41737e0f8a74f97a14ccefd1148187271634f3c"
+dependencies = [
+ "bitflags",
+]
 
 [[package]]
 name = "rust_with_cffi"
@@ -217,15 +179,15 @@ checksum = "d29ab0c6d3fc0ee92fe66e2d99f700eab17a8d57d1c1d3b748380fb20baa78cd"
 
 [[package]]
 name = "smallvec"
-version = "1.4.2"
+version = "1.8.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "fbee7696b84bbf3d89a1c2eccff0850e3047ed46bfcd2e92c29a2d074d57e252"
+checksum = "f2dd574626839106c320a323308629dcb1acfc96e32a8cba364ddc61ac23ee83"
 
 [[package]]
 name = "syn"
-version = "1.0.41"
+version = "1.0.86"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6690e3e9f692504b941dc6c3b188fd28df054f7fb8469ab40680df52fdcc842b"
+checksum = "8a65b3f4ffa0092e9887669db0eae07941f023991ab58ea44da8fe8e2d511c6b"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -234,15 +196,15 @@ dependencies = [
 
 [[package]]
 name = "unicode-xid"
-version = "0.2.1"
+version = "0.2.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f7fe0bb3479651439c9112f72b6c505038574c9fbb575ed1bf3b797fa39dd564"
+checksum = "8ccb82d61f80a663efe1f787a51b16b5a51e3314d6ac365b08639f52387b33f3"
 
 [[package]]
 name = "unindent"
-version = "0.1.6"
+version = "0.1.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "af41d708427f8fd0e915dcebb2cae0f0e6acb2a939b2d399c265c39a38a18942"
+checksum = "514672a55d7380da379785a4d70ca8386c8883ff7eaae877be4d2081cebe73d8"
 
 [[package]]
 name = "winapi"
diff --git a/examples/rust_with_cffi/Cargo.toml b/examples/rust_with_cffi/Cargo.toml
index e7914f9a..6064e38b 100644
--- a/examples/rust_with_cffi/Cargo.toml
+++ b/examples/rust_with_cffi/Cargo.toml
@@ -5,7 +5,7 @@ authors = ["Alex Gaynor <alex.gaynor@gmail.com>"]
 edition = "2018"
 
 [dependencies]
-pyo3 = { version = "0.15.1", features = ["extension-module"] }
+pyo3 = { version = "0.16.1", features = ["extension-module"] }
 
 [lib]
 name = "rust_with_cffi"
diff --git a/examples/rust_with_cffi/noxfile.py b/examples/rust_with_cffi/noxfile.py
index 85679e36..ada9b29f 100644
--- a/examples/rust_with_cffi/noxfile.py
+++ b/examples/rust_with_cffi/noxfile.py
@@ -1,3 +1,4 @@
+import sys
 from os.path import dirname
 
 import nox
@@ -7,6 +8,7 @@
 
 @nox.session()
 def test(session: nox.Session):
-    session.install(SETUPTOOLS_RUST, "pytest", "cffi")
-    session.install(".")
-    session.run("pytest", *session.posargs)
+    if sys.version_info >= (3, 7):
+        session.install(SETUPTOOLS_RUST, "pytest", "cffi")
+        session.install(".")
+        session.run("pytest", *session.posargs)