diff --git a/library/stdarch/crates/intrinsic-test/src/json_parser.rs b/library/stdarch/crates/intrinsic-test/src/json_parser.rs
index acb1e53327b0..bc6fa4a9edea 100644
--- a/library/stdarch/crates/intrinsic-test/src/json_parser.rs
+++ b/library/stdarch/crates/intrinsic-test/src/json_parser.rs
@@ -29,7 +29,6 @@ pub enum ArgPrep {
 }
 
 #[derive(Deserialize, Debug)]
-#[serde(deny_unknown_fields)]
 struct JsonIntrinsic {
     #[serde(rename = "SIMD_ISA")]
     simd_isa: String,