diff --git a/Cargo.lock b/Cargo.lock
index 61e7596..3c151bf 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -496,15 +496,6 @@ dependencies = [
  "syn",
 ]
 
-[[package]]
-name = "indoc"
-version = "2.0.7"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "79cf5c93f93228cf8efb3ba362535fb11199ac548a09ce117c9b1adc3030d706"
-dependencies = [
- "rustversion",
-]
-
 [[package]]
 name = "is-terminal"
 version = "0.4.17"
@@ -580,15 +571,6 @@ version = "2.8.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f8ca58f447f06ed17d5fc4043ce1b10dd205e060fb3ce5b979b8ed8e59ff3f79"
 
-[[package]]
-name = "memoffset"
-version = "0.9.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "488016bfae457b036d996092f6cb448677611ce4449e970ceaf42695203f218a"
-dependencies = [
- "autocfg",
-]
-
 [[package]]
 name = "miniz_oxide"
 version = "0.8.9"
@@ -709,37 +691,32 @@ dependencies = [
 
 [[package]]
 name = "pyo3"
-version = "0.24.2"
+version = "0.28.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e5203598f366b11a02b13aa20cab591229ff0a89fd121a308a5df751d5fc9219"
+checksum = "91fd8e38a3b50ed1167fb981cd6fd60147e091784c427b8f7183a7ee32c31c12"
 dependencies = [
- "cfg-if",
- "indoc",
  "libc",
- "memoffset",
  "once_cell",
  "portable-atomic",
  "pyo3-build-config",
  "pyo3-ffi",
  "pyo3-macros",
- "unindent",
 ]
 
 [[package]]
 name = "pyo3-build-config"
-version = "0.24.2"
+version = "0.28.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "99636d423fa2ca130fa5acde3059308006d46f98caac629418e53f7ebb1e9999"
+checksum = "e368e7ddfdeb98c9bca7f8383be1648fd84ab466bf2bc015e94008db6d35611e"
 dependencies = [
- "once_cell",
  "target-lexicon",
 ]
 
 [[package]]
 name = "pyo3-ffi"
-version = "0.24.2"
+version = "0.28.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "78f9cf92ba9c409279bc3305b5409d90db2d2c22392d443a87df3a1adad59e33"
+checksum = "7f29e10af80b1f7ccaf7f69eace800a03ecd13e883acfacc1e5d0988605f651e"
 dependencies = [
  "libc",
  "pyo3-build-config",
@@ -747,9 +724,9 @@ dependencies = [
 
 [[package]]
 name = "pyo3-macros"
-version = "0.24.2"
+version = "0.28.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0b999cb1a6ce21f9a6b147dcf1be9ffedf02e0043aec74dc390f3007047cecd9"
+checksum = "df6e520eff47c45997d2fc7dd8214b25dd1310918bbb2642156ef66a67f29813"
 dependencies = [
  "proc-macro2",
  "pyo3-macros-backend",
@@ -759,9 +736,9 @@ dependencies = [
 
 [[package]]
 name = "pyo3-macros-backend"
-version = "0.24.2"
+version = "0.28.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "822ece1c7e1012745607d5cf0bcb2874769f0f7cb34c4cde03b9358eb9ef911a"
+checksum = "c4cdc218d835738f81c2338f822078af45b4afdf8b2e33cbb5916f108b813acb"
 dependencies = [
  "heck",
  "proc-macro2",
@@ -1068,12 +1045,6 @@ version = "1.0.24"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e6e4313cd5fcd3dad5cafa179702e2b244f760991f45397d14d4ebf38247da75"
 
-[[package]]
-name = "unindent"
-version = "0.2.4"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7264e107f553ccae879d21fbea1d6724ac785e8c3bfc762137959b5802826ef3"
-
 [[package]]
 name = "utf8parse"
 version = "0.2.2"
diff --git a/rvt-py/Cargo.toml b/rvt-py/Cargo.toml
index d0ce2ca..c8bd559 100644
--- a/rvt-py/Cargo.toml
+++ b/rvt-py/Cargo.toml
@@ -25,7 +25,7 @@ rvt = { path = "..", version = "=0.1.2" }
 # Python bindings. `abi3-py38` makes a single wheel compatible with
 # every Python >= 3.8. `extension-module` tells pyo3 this build is
 # the .so/.pyd extension, not a standalone executable.
-pyo3 = { version = "0.24", features = ["extension-module", "abi3-py38"] }
+pyo3 = { version = "0.28", features = ["extension-module", "abi3-py38"] }
 
 # Used by the Python bindings for JSON serialisation at the FFI
 # boundary. Matches the root crate's version so serde derives stay