diff --git a/compiler/rustc_parse/src/parser/expr.rs b/compiler/rustc_parse/src/parser/expr.rs
index cf5d65708ab0..bb3cddccce25 100644
--- a/compiler/rustc_parse/src/parser/expr.rs
+++ b/compiler/rustc_parse/src/parser/expr.rs
@@ -1206,7 +1206,7 @@ fn parse_floating_field_access(&mut self) -> PResult<'a, P<[Ident]>> {
     }
 
     fn mk_expr_tuple_field_access(
-        &mut self,
+        &self,
         lo: Span,
         ident_span: Span,
         base: P<Expr>,