diff --git a/Cargo.toml b/Cargo.toml
index 6ee1c20d..3a72b361 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -23,7 +23,7 @@ indoc = { version = "0.3.4", optional = true }
 inventory = { version = "0.1.4", optional = true }
 libc = "0.2.62"
 parking_lot = "0.10.2"
-num-bigint = { version = "0.2", optional = true }
+num-bigint = { version = "0.3", optional = true }
 num-complex = { version = "0.3", optional = true }
 paste = { version = "0.1.6", optional = true }
 pyo3cls = { path = "pyo3cls", version = "=0.10.1", optional = true }