1 files changed, 4 insertions, 0 deletions
diff --git a/compiler/rustc_parse/src/parser/pat.rs b/compiler/rustc_parse/src/parser/pat.rs
index ead00c3f0d4..59e0cd92c4c 100644
--- a/compiler/rustc_parse/src/parser/pat.rs
+++ b/compiler/rustc_parse/src/parser/pat.rs
@@ -779,6 +779,10 @@ impl<'a> Parser<'a> {
             self.ban_mut_general_pat(mut_span, &pat, changed_any_binding);
         }
 
+        if matches!(pat.kind, PatKind::Ident(BindingAnnotation(ByRef::Yes(_), Mutability::Mut), ..))
+        {
+            self.psess.gated_spans.gate(sym::mut_ref, pat.span);
+        }
         Ok(pat.into_inner().kind)
     }