diff --git a/crates/ra_hir_def/src/body/lower.rs b/crates/ra_hir_def/src/body/lower.rs
index df560155c6c..4f23cb5c854 100644
--- a/crates/ra_hir_def/src/body/lower.rs
+++ b/crates/ra_hir_def/src/body/lower.rs
@@ -372,7 +372,7 @@ fn collect_expr(&mut self, expr: ast::Expr) -> ExprId {
             }
             ast::Expr::RefExpr(e) => {
                 let expr = self.collect_expr_opt(e.expr());
-                let mutability = Mutability::from_mutable(e.is_mut());
+                let mutability = Mutability::from_mutable(e.mut_kw_token().is_some());
                 self.alloc_expr(Expr::Ref { expr, mutability }, syntax_ptr)
             }
             ast::Expr::PrefixExpr(e) => {
diff --git a/crates/ra_syntax/src/ast/expr_extensions.rs b/crates/ra_syntax/src/ast/expr_extensions.rs
index 003ee00b3e5..5c5f196224b 100644
--- a/crates/ra_syntax/src/ast/expr_extensions.rs
+++ b/crates/ra_syntax/src/ast/expr_extensions.rs
@@ -49,10 +49,6 @@ fn blocks(&self) -> AstChildren<ast::BlockExpr> {
 }
 
 impl ast::RefExpr {
-    pub fn is_mut(&self) -> bool {
-        self.syntax().children_with_tokens().any(|n| n.kind() == T![mut])
-    }
-
     pub fn raw_token(&self) -> Option<SyntaxToken> {
         None // FIXME: implement &raw
     }