diff --git a/Cargo.toml b/Cargo.toml
index 7fb69fd5..5663d8fb 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -19,7 +19,7 @@ ethereum-types = "0.13.0"
 futures = "0.3.5"
 futures-timer = "3.0.2"
 hex = "0.4"
-idna = "0.3"
+idna = "0.4"
 jsonrpc-core = "18.0.0"
 log = "0.4.6"
 parking_lot = "0.12.0"