diff --git a/Cargo.lock b/Cargo.lock
index da8edf7..b78d6da 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -63,6 +63,12 @@ dependencies = [
  "wasi",
 ]
 
+[[package]]
+name = "heck"
+version = "0.4.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "95505c38b4572b2d910cecb0281560f54b440a19336cbbcb27bf6ce6adc6f5a8"
+
 [[package]]
 name = "html5ever"
 version = "0.26.0"
@@ -74,7 +80,7 @@ dependencies = [
  "markup5ever",
  "proc-macro2",
  "quote",
- "syn",
+ "syn 1.0.109",
 ]
 
 [[package]]
@@ -89,9 +95,9 @@ dependencies = [
 
 [[package]]
 name = "indoc"
-version = "1.0.9"
+version = "2.0.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "bfa799dd5ed20a7e349f3b4639aa80d74549c81716d9ec4f994c9b5815598306"
+checksum = "1e186cfbae8084e513daff4240b4797e342f988cecda4fb6c939150f96315fd8"
 
 [[package]]
 name = "libc"
@@ -260,9 +266,9 @@ dependencies = [
 
 [[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",
@@ -277,9 +283,9 @@ 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",
@@ -287,9 +293,9 @@ 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",
@@ -297,25 +303,26 @@ 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 2.0.32",
 ]
 
 [[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 2.0.32",
 ]
 
 [[package]]
@@ -427,6 +434,17 @@ dependencies = [
  "unicode-ident",
 ]
 
+[[package]]
+name = "syn"
+version = "2.0.32"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "239814284fd6f1a4ffe4ca893952cdd93c224b6a1571c9a9eadd670295c0c9e2"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "unicode-ident",
+]
+
 [[package]]
 name = "target-lexicon"
 version = "0.12.8"
@@ -482,9 +500,9 @@ dependencies = [
 
 [[package]]
 name = "unindent"
-version = "0.1.11"
+version = "0.2.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e1766d682d402817b5ac4490b3c3002d91dfa0d22812f341609f97b08757359c"
+checksum = "c7de7d73e1754487cb58364ee906a499937a0dfabd86bcb980fa99ec8c8fa2ce"
 
 [[package]]
 name = "url"
diff --git a/Cargo.toml b/Cargo.toml
index fcad39b..12b7570 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -15,4 +15,4 @@ crate-type = ["cdylib"]
 
 [dependencies]
 ammonia = "3.3.0"
-pyo3 = { version = "0.19.2", features = ["abi3-py37", "extension-module"] }
+pyo3 = { version = "0.20.0", features = ["abi3-py37", "extension-module"] }