diff --git a/Cargo.toml b/Cargo.toml
index 8f98d49..95fe342 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -17,5 +17,5 @@ num-traits = {version = "0.1.32", default-features = false}
 serde = { version = "1.0", features = ["serde_derive"], optional = true }
 
 [dev-dependencies]
-rand = "0.3.7"
+rand = "0.4"
 serde_test = "1.0"