1 files changed, 3 insertions, 4 deletions
diff --git a/compiler/rustc_middle/src/mir/query.rs b/compiler/rustc_middle/src/mir/query.rs
index efd7357afc4..a8a4532223c 100644
--- a/compiler/rustc_middle/src/mir/query.rs
+++ b/compiler/rustc_middle/src/mir/query.rs
@@ -130,10 +130,9 @@ pub struct UnsafetyCheckResult {
 }
 
 rustc_index::newtype_index! {
-    pub struct GeneratorSavedLocal {
-        derive [HashStable]
-        DEBUG_FORMAT = "_{}",
-    }
+    #[derive(HashStable)]
+    #[debug_format = "_{}"]
+    pub struct GeneratorSavedLocal {}
 }
 
 /// The layout of generator state.