1 files changed, 3 insertions, 3 deletions
diff --git a/compiler/rustc_query_system/src/ich/impls_syntax.rs b/compiler/rustc_query_system/src/ich/impls_syntax.rs
index 78c37688d34..29a28b10a06 100644
--- a/compiler/rustc_query_system/src/ich/impls_syntax.rs
+++ b/compiler/rustc_query_system/src/ich/impls_syntax.rs
@@ -115,9 +115,9 @@ impl<'tcx> HashStable<StableHashingContext<'tcx>> for rustc_feature::Features {
         self.enabled_lang_features().hash_stable(hcx, hasher);
         self.enabled_lib_features().hash_stable(hcx, hasher);
 
-        self.all_lang_features()[..].hash_stable(hcx, hasher);
-        for feature in rustc_feature::UNSTABLE_FEATURES.iter() {
-            feature.feature.name.hash_stable(hcx, hasher);
+        // FIXME: why do we hash something that is a compile-time constant?
+        for feature in rustc_feature::UNSTABLE_LANG_FEATURES.iter() {
+            feature.name.hash_stable(hcx, hasher);
         }
     }
 }