diff --git a/Cargo.toml b/Cargo.toml
index e6d1f45..5ad1902 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -19,5 +19,5 @@ name = "cipher_crypt"
 lazy_static = "^1"
 maplit = "^1.0.1"
 lipsum = "^0.6"
-num = "^0.1"
+num = "^0.4"
 rulinalg = "^0.4"