diff --git a/lib/Cargo.toml b/lib/Cargo.toml
index 2f08aba..9d5912e 100644
--- a/lib/Cargo.toml
+++ b/lib/Cargo.toml
@@ -22,6 +22,7 @@ secp256k1 = "=0.15.0"
 sha2 = "0.8.0"
 ripemd160 = "0.8.0"
 lazy_static = "1.2.0"
+num-integer = "0.1.44"
 rust-embed = { version = "5.1.0", features = ["debug-embed"] }
 rand = "0.7.2"
 sodiumoxide = "0.2.5"