diff --git a/Cargo.toml b/Cargo.toml
index 25755d5..4733c33 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -21,7 +21,8 @@ simd_asm = ["simd_opt"]
 std = []
 
 [dependencies]
-arrayvec = { version = "0.5.1", default-features = false }
+arrayvec = { version = "0.4.0", default-features = false }
+
 constant_time_eq = "0.1.0"
 
 [dev-dependencies]