diff --git a/Cargo.lock b/Cargo.lock
index 218b02a..18e99bf 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -143,6 +143,12 @@ dependencies = [
  "windows-targets 0.48.5",
 ]
 
+[[package]]
+name = "portable-atomic"
+version = "1.6.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7170ef9988bc169ba16dd36a7fa041e5c4cbeb6a35b76d4c03daded371eae7c0"
+
 [[package]]
 name = "proc-macro2"
 version = "1.0.78"
@@ -154,15 +160,16 @@ dependencies = [
 
 [[package]]
 name = "pyo3"
-version = "0.20.2"
+version = "0.21.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9a89dc7a5850d0e983be1ec2a463a171d20990487c3cfcd68b5363f1ee3d6fe0"
+checksum = "a5e00b96a521718e08e03b1a622f01c8a8deb50719335de3f60b3b3950f069d8"
 dependencies = [
  "cfg-if",
  "indoc",
  "libc",
  "memoffset",
  "parking_lot",
+ "portable-atomic",
  "pyo3-build-config",
  "pyo3-ffi",
  "pyo3-macros",
@@ -171,9 +178,9 @@ dependencies = [
 
 [[package]]
 name = "pyo3-build-config"
-version = "0.20.2"
+version = "0.21.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "07426f0d8fe5a601f26293f300afd1a7b1ed5e78b2a705870c5f30893c5163be"
+checksum = "7883df5835fafdad87c0d888b266c8ec0f4c9ca48a5bed6bbb592e8dedee1b50"
 dependencies = [
  "once_cell",
  "target-lexicon",
@@ -181,9 +188,9 @@ dependencies = [
 
 [[package]]
 name = "pyo3-ffi"
-version = "0.20.2"
+version = "0.21.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "dbb7dec17e17766b46bca4f1a4215a85006b4c2ecde122076c562dd058da6cf1"
+checksum = "01be5843dc60b916ab4dad1dca6d20b9b4e6ddc8e15f50c47fe6d85f1fb97403"
 dependencies = [
  "libc",
  "pyo3-build-config",
@@ -191,9 +198,9 @@ dependencies = [
 
 [[package]]
 name = "pyo3-macros"
-version = "0.20.2"
+version = "0.21.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "05f738b4e40d50b5711957f142878cfa0f28e054aa0ebdfc3fd137a843f74ed3"
+checksum = "77b34069fc0682e11b31dbd10321cbf94808394c56fd996796ce45217dfac53c"
 dependencies = [
  "proc-macro2",
  "pyo3-macros-backend",
@@ -203,12 +210,13 @@ dependencies = [
 
 [[package]]
 name = "pyo3-macros-backend"
-version = "0.20.2"
+version = "0.21.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0fc910d4851847827daf9d6cdd4a823fbdaab5b8818325c5e97a86da79e8881f"
+checksum = "08260721f32db5e1a5beae69a55553f56b99bd0e1c3e6e0a5e8851a9d0f5a85c"
 dependencies = [
  "heck",
  "proc-macro2",
+ "pyo3-build-config",
  "quote",
  "syn",
 ]
diff --git a/Cargo.toml b/Cargo.toml
index 2d717e5..c16ff1e 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -17,7 +17,7 @@ crate-type = ["cdylib"]
 winpty-rs = "0.3.15"
 
 [dependencies.pyo3]
-version = "0.20.2"
+version = "0.21.2"
 features = ["extension-module"]
 
 [package.metadata.docs.rs]