diff --git a/Cargo.toml b/Cargo.toml
index 79c97a2..706cf21 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -8,7 +8,7 @@ description = "x25519 & chacha20poly1305"
 repository = "https://github.com/entropyxyz/x25519-chacha20poly1305"
 
 [dependencies]
-hex = "*"
+hex = "0.4.3"
 bip39 = { git = "https://github.com/infincia/bip39-rs.git", tag = "v0.6.0-beta.1" }
 wasm-bindgen = "0.2.83"
 x25519-dalek = { version = "2.0.0", features = ["static_secrets"] }