diff --git a/Cargo.toml b/Cargo.toml
index 4c1996c..e5a1ea1 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -23,7 +23,7 @@ extension-module = ["pyo3/extension-module"]
 num-complex = { version = "0.4.0", optional = true }
 num-traits = { version = "0.2.15", optional = true }
 paste = "1.0"
-pyo3 = { version = "0.20", default-features = false, features = ["macros", "multiple-pymethods"] }
+pyo3 = { version = "0.21", default-features = false, features = ["macros", "multiple-pymethods"] }
 # time has a "stable minus two MSRV" policy, which doesn't jive with
 # our more permissive MSRV
 # https://github.com/time-rs/time/discussions/535