diff --git a/Cargo.lock b/Cargo.lock
index 11a8e92..5d5b7a8 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -471,9 +471,9 @@ checksum = "f8ca58f447f06ed17d5fc4043ce1b10dd205e060fb3ce5b979b8ed8e59ff3f79"
 
 [[package]]
 name = "num-bigint"
-version = "0.4.6"
+version = "0.5.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a5e44f723f1133c9deac646763579fdb3ac745e418f2a7af9cd0c431da1f20b9"
+checksum = "7032fbb7ef662c18e806aa75b311f68ddf5c94e8fc62832c0039d79095ab6abf"
 dependencies = [
  "num-integer",
  "num-traits",
diff --git a/spake2/Cargo.toml b/spake2/Cargo.toml
index 4e89620..655ec3d 100644
--- a/spake2/Cargo.toml
+++ b/spake2/Cargo.toml
@@ -26,7 +26,7 @@ getrandom = { version = "0.4", optional = true, features = ["sys_rng"] }
 [dev-dependencies]
 bencher = "0.1"
 hex = "0.4"
-num-bigint = "0.4"
+num-bigint = "0.5"
 
 [features]
 default = []