diff --git a/Cargo.toml b/Cargo.toml
index df26c92..05dbc67 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -40,7 +40,10 @@ anyhow = "1.0"
 paste = "1.0"
 #num-complex = "0.3"
 netcdf = { version = "0.7", optional = true, default-features = false }
-pyo3 = { version = "0.23", optional = true, features = ["auto-initialize"] }
+pyo3 = { version = "0.22", optional = true, features = [
+  "auto-initialize",
+  "gil-refs",
+] }
 blas = { version = "0.22", optional = true }
 lapack = { version = "0.19", optional = true }
 serde = { version = "1.0", features = ["derive"], optional = true }