diff --git a/examples/html-py-ever/Cargo.lock b/examples/html-py-ever/Cargo.lock
index 13cf3d00..0eecc439 100644
--- a/examples/html-py-ever/Cargo.lock
+++ b/examples/html-py-ever/Cargo.lock
@@ -46,7 +46,7 @@ dependencies = [
  "proc-macro2",
  "quote",
  "smallvec",
- "syn",
+ "syn 1.0.89",
 ]
 
 [[package]]
@@ -56,7 +56,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "dfae75de57f2b2e85e8768c3ea840fd159c8f33e2b6522c7835b7abac81be16e"
 dependencies = [
  "quote",
- "syn",
+ "syn 1.0.89",
 ]
 
 [[package]]
@@ -69,7 +69,7 @@ dependencies = [
  "proc-macro2",
  "quote",
  "rustc_version",
- "syn",
+ "syn 1.0.89",
 ]
 
 [[package]]
@@ -117,6 +117,12 @@ dependencies = [
  "wasi",
 ]
 
+[[package]]
+name = "heck"
+version = "0.4.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "95505c38b4572b2d910cecb0281560f54b440a19336cbbcb27bf6ce6adc6f5a8"
+
 [[package]]
 name = "html-py-ever"
 version = "0.1.0"
@@ -137,17 +143,14 @@ dependencies = [
  "markup5ever",
  "proc-macro2",
  "quote",
- "syn",
+ "syn 1.0.89",
 ]
 
 [[package]]
 name = "indoc"
-version = "1.0.4"
+version = "2.0.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e7906a9fababaeacb774f72410e497a1d18de916322e33797bb2cd29baa23c9e"
-dependencies = [
- "unindent",
-]
+checksum = "1e186cfbae8084e513daff4240b4797e342f988cecda4fb6c939150f96315fd8"
 
 [[package]]
 name = "instant"
@@ -326,7 +329,7 @@ dependencies = [
  "proc-macro-hack",
  "proc-macro2",
  "quote",
- "syn",
+ "syn 1.0.89",
 ]
 
 [[package]]
@@ -367,18 +370,18 @@ checksum = "dbf0c48bc1d91375ae5c3cd81e3722dff1abcf81a30960240640d223f59fe0e5"
 
 [[package]]
 name = "proc-macro2"
-version = "1.0.36"
+version = "1.0.69"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c7342d5883fbccae1cc37a2353b09c87c9b0f3afd73f5fb9bba687a1f733b029"
+checksum = "134c189feb4956b20f6f547d2cf727d4c0fe06722b20a0eec87ed445a97f92da"
 dependencies = [
- "unicode-xid",
+ "unicode-ident",
 ]
 
 [[package]]
 name = "pyo3"
-version = "0.19.2"
+version = "0.20.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e681a6cfdc4adcc93b4d3cf993749a4552018ee0a9b65fc0ccfad74352c72a38"
+checksum = "04e8453b658fe480c3e70c8ed4e3d3ec33eb74988bd186561b0cc66b85c3bc4b"
 dependencies = [
  "cfg-if",
  "indoc",
@@ -393,9 +396,9 @@ dependencies = [
 
 [[package]]
 name = "pyo3-build-config"
-version = "0.19.2"
+version = "0.20.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "076c73d0bc438f7a4ef6fdd0c3bb4732149136abd952b110ac93e4edb13a6ba5"
+checksum = "a96fe70b176a89cff78f2fa7b3c930081e163d5379b4dcdf993e3ae29ca662e5"
 dependencies = [
  "once_cell",
  "target-lexicon",
@@ -403,9 +406,9 @@ dependencies = [
 
 [[package]]
 name = "pyo3-ffi"
-version = "0.19.2"
+version = "0.20.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e53cee42e77ebe256066ba8aa77eff722b3bb91f3419177cf4cd0f304d3284d9"
+checksum = "214929900fd25e6604661ed9cf349727c8920d47deff196c4e28165a6ef2a96b"
 dependencies = [
  "libc",
  "pyo3-build-config",
@@ -413,32 +416,33 @@ dependencies = [
 
 [[package]]
 name = "pyo3-macros"
-version = "0.19.2"
+version = "0.20.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "dfeb4c99597e136528c6dd7d5e3de5434d1ceaf487436a3f03b2d56b6fc9efd1"
+checksum = "dac53072f717aa1bfa4db832b39de8c875b7c7af4f4a6fe93cdbf9264cf8383b"
 dependencies = [
  "proc-macro2",
  "pyo3-macros-backend",
  "quote",
- "syn",
+ "syn 2.0.38",
 ]
 
 [[package]]
 name = "pyo3-macros-backend"
-version = "0.19.2"
+version = "0.20.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "947dc12175c254889edc0c02e399476c2f652b4b9ebd123aa655c224de259536"
+checksum = "7774b5a8282bd4f25f803b1f0d945120be959a36c72e08e7cd031c792fdfd424"
 dependencies = [
+ "heck",
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.38",
 ]
 
 [[package]]
 name = "quote"
-version = "1.0.16"
+version = "1.0.33"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b4af2ec4714533fcdf07e886f17025ace8b997b9ce51204ee69b6da831c3da57"
+checksum = "5267fca4496028628a95160fc423a33e8b2e6af8a5302579e322e4b520293cae"
 dependencies = [
  "proc-macro2",
 ]
@@ -615,6 +619,17 @@ dependencies = [
  "unicode-xid",
 ]
 
+[[package]]
+name = "syn"
+version = "2.0.38"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e96b79aaa137db8f61e26363a0c9b47d8b4ec75da28b7d1d614c2303e232408b"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "unicode-ident",
+]
+
 [[package]]
 name = "target-lexicon"
 version = "0.12.3"
@@ -638,6 +653,12 @@ version = "0.1.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "8eaa81235c7058867fa8c0e7314f33dcce9c215f535d1913822a2b3f5e289f3c"
 
+[[package]]
+name = "unicode-ident"
+version = "1.0.12"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3354b9ac3fae1ff6755cb6db53683adb661634f67557942dea4facebec0fee4b"
+
 [[package]]
 name = "unicode-xid"
 version = "0.2.2"
@@ -646,9 +667,9 @@ checksum = "8ccb82d61f80a663efe1f787a51b16b5a51e3314d6ac365b08639f52387b33f3"
 
 [[package]]
 name = "unindent"
-version = "0.1.8"
+version = "0.2.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "514672a55d7380da379785a4d70ca8386c8883ff7eaae877be4d2081cebe73d8"
+checksum = "c7de7d73e1754487cb58364ee906a499937a0dfabd86bcb980fa99ec8c8fa2ce"
 
 [[package]]
 name = "utf-8"
diff --git a/examples/html-py-ever/Cargo.toml b/examples/html-py-ever/Cargo.toml
index ba26e10a..f6f41955 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 = "0.19.2", features = ["extension-module"] }
+pyo3 = { version = "0.20.0", features = ["extension-module"] }
 tendril = "0.4.3"
 
 [lib]