diff --git a/deny.toml b/deny.toml
index a2e17e9d5e..533ded2bdc 100644
--- a/deny.toml
+++ b/deny.toml
@@ -18,6 +18,9 @@ ignore = [
 
     # Unmaintained instant
     "RUSTSEC-2024-0384",
+
+    # idna 0.5.0
+    "RUSTSEC-2024-0421",
 ]
 
 [bans]