diff --git a/library/stdarch/crates/intrinsic-test/src/json_parser.rs b/library/stdarch/crates/intrinsic-test/src/json_parser.rs
index 8b3c7869c64e..70ab51561bcb 100644
--- a/library/stdarch/crates/intrinsic-test/src/json_parser.rs
+++ b/library/stdarch/crates/intrinsic-test/src/json_parser.rs
@@ -18,6 +18,7 @@ struct ReturnType {
 pub enum ArgPrep {
     Register {
         #[serde(rename = "register")]
+        #[allow(dead_code)]
         reg: String,
     },
     Immediate {