diff --git a/Cargo.toml b/Cargo.toml
index 52f8a00..79bfba9 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -8,7 +8,7 @@ repository = "https://github.com/davesque/blake2b-py"
 description = "Blake2b hashing in Rust with Python bindings."
 
 [dependencies]
-pyo3 = { version = "~0.15", features = ["extension-module"] }
+pyo3 = { version = "~0.16", features = ["extension-module"] }
 
 [dev-dependencies]
 hex = "~0.4"