diff --git a/crates/ra_parser/src/grammar/expressions/atom.rs b/crates/ra_parser/src/grammar/expressions/atom.rs
index ab8fb9f6e906..bc942ae01028 100644
--- a/crates/ra_parser/src/grammar/expressions/atom.rs
+++ b/crates/ra_parser/src/grammar/expressions/atom.rs
@@ -414,8 +414,6 @@ pub(crate) fn match_arm_list(p: &mut Parser) {
 //         X | Y if Z => (),
 //         | X | Y if Z => (),
 //         | X => (),
-//         box X => (),
-//         Some(box X) => (),
 //     };
 // }
 fn match_arm(p: &mut Parser) -> BlockLike {
diff --git a/crates/ra_parser/src/grammar/patterns.rs b/crates/ra_parser/src/grammar/patterns.rs
index 67f1548a72a7..f9e6de13c8c7 100644
--- a/crates/ra_parser/src/grammar/patterns.rs
+++ b/crates/ra_parser/src/grammar/patterns.rs
@@ -269,11 +269,6 @@ fn bind_pat(p: &mut Parser, with_at: bool) -> CompletedMarker {
     m.complete(p, BIND_PAT)
 }
 
-// test_err ref_box_pat
-// fn main() {
-//     let ref box i = ();
-// }
-
 // test box_pat
 // fn main() {
 //     let box i = ();
diff --git a/crates/ra_syntax/test_data/parser/err/0034_bad_box_pattern.rs b/crates/ra_syntax/test_data/parser/err/0034_bad_box_pattern.rs
new file mode 100644
index 000000000000..d3fa2e468cc7
--- /dev/null
+++ b/crates/ra_syntax/test_data/parser/err/0034_bad_box_pattern.rs
@@ -0,0 +1,6 @@
+fn main() {
+    let ref box i = ();
+    let mut box i = ();
+    let ref mut box i = ();
+}
+