1 files changed, 16 insertions, 8 deletions
diff --git a/src/libsyntax_ext/lib.rs b/src/libsyntax_ext/lib.rs
index 62530f4fe7b..da0f8ca6da0 100644
--- a/src/libsyntax_ext/lib.rs
+++ b/src/libsyntax_ext/lib.rs
@@ -72,6 +72,7 @@ pub fn register_builtins(resolver: &mut dyn syntax::ext::base::Resolver,
     let mut register = |name, ext| {
         resolver.add_builtin(ast::Ident::with_empty_ctxt(name), Lrc::new(ext));
     };
+
     macro_rules! register {
         ($( $name:ident: $f:expr, )*) => { $(
             register(sym::$name, SyntaxExtension::default(
@@ -125,24 +126,31 @@ pub fn register_builtins(resolver: &mut dyn syntax::ext::base::Resolver,
         trace_macros: trace_macros::expand_trace_macros,
     }
 
+    let allow_internal_unstable = Some([sym::test, sym::rustc_attrs][..].into());
     register(sym::test_case, SyntaxExtension {
         stability: Some(Stability::unstable(
             sym::custom_test_frameworks,
             Some(Symbol::intern(EXPLAIN_CUSTOM_TEST_FRAMEWORKS)),
             50297,
         )),
+        allow_internal_unstable: allow_internal_unstable.clone(),
         ..SyntaxExtension::default(
             SyntaxExtensionKind::LegacyAttr(Box::new(test_case::expand)), edition
         )
     });
-    register(sym::test, SyntaxExtension::default(
-        SyntaxExtensionKind::LegacyAttr(Box::new(test::expand_test)), edition
-    ));
-    register(sym::bench, SyntaxExtension::default(
-        SyntaxExtensionKind::LegacyAttr(Box::new(test::expand_bench)), edition
-    ));
-
-    // format_args uses `unstable` things internally.
+    register(sym::test, SyntaxExtension {
+        allow_internal_unstable: allow_internal_unstable.clone(),
+        ..SyntaxExtension::default(
+            SyntaxExtensionKind::LegacyAttr(Box::new(test::expand_test)), edition
+        )
+    });
+    register(sym::bench, SyntaxExtension {
+        allow_internal_unstable,
+        ..SyntaxExtension::default(
+            SyntaxExtensionKind::LegacyAttr(Box::new(test::expand_bench)), edition
+        )
+    });
+
     let allow_internal_unstable = Some([sym::fmt_internals][..].into());
     register(sym::format_args, SyntaxExtension {
         allow_internal_unstable: allow_internal_unstable.clone(),