diff --git a/crates/libsyntax2/src/grammar/expressions/atom.rs b/crates/libsyntax2/src/grammar/expressions/atom.rs
index fdb4718ba6..8335c700f8 100644
--- a/crates/libsyntax2/src/grammar/expressions/atom.rs
+++ b/crates/libsyntax2/src/grammar/expressions/atom.rs
@@ -323,11 +323,9 @@ fn match_arm_list(p: &mut Parser) {
 // }
 fn match_arm(p: &mut Parser) -> BlockLike {
     let m = p.start();
-    loop {
+    patterns::pattern_r(p, TokenSet::EMPTY);
+    while p.eat(PIPE) {
         patterns::pattern(p);
-        if !p.eat(PIPE) {
-            break;
-        }
     }
     if p.eat(IF_KW) {
         expr_no_struct(p);
diff --git a/crates/libsyntax2/src/grammar/patterns.rs b/crates/libsyntax2/src/grammar/patterns.rs
index 6dd3ab2fa1..29a55cb46d 100644
--- a/crates/libsyntax2/src/grammar/patterns.rs
+++ b/crates/libsyntax2/src/grammar/patterns.rs
@@ -8,7 +8,11 @@ pub(super) const PATTERN_FIRST: TokenSet =
     ];
 
 pub(super) fn pattern(p: &mut Parser) {
-    if let Some(lhs) = atom_pat(p) {
+    pattern_r(p, PAT_RECOVERY_SET)
+}
+
+pub(super) fn pattern_r(p: &mut Parser, recovery_set: TokenSet) {
+    if let Some(lhs) = atom_pat(p, recovery_set) {
         // test range_pat
         // fn main() {
         //     match 92 { 0 ... 100 => () }
@@ -16,7 +20,7 @@ pub(super) fn pattern(p: &mut Parser) {
         if p.at(DOTDOTDOT) {
             let m = lhs.precede(p);
             p.bump();
-            atom_pat(p);
+            atom_pat(p, recovery_set);
             m.complete(p, RANGE_PAT);
         }
     }
@@ -26,7 +30,7 @@ const PAT_RECOVERY_SET: TokenSet =
     token_set![LET_KW, IF_KW, WHILE_KW, LOOP_KW, MATCH_KW, R_PAREN, COMMA];
 
 
-fn atom_pat(p: &mut Parser) -> Option<CompletedMarker> {
+fn atom_pat(p: &mut Parser, recovery_set: TokenSet) -> Option<CompletedMarker> {
     let la0 = p.nth(0);
     let la1 = p.nth(1);
     if la0 == REF_KW || la0 == MUT_KW
@@ -56,7 +60,7 @@ fn atom_pat(p: &mut Parser) -> Option<CompletedMarker> {
         L_PAREN => tuple_pat(p),
         L_BRACK => slice_pat(p),
         _ => {
-            p.err_recover("expected pattern", PAT_RECOVERY_SET);
+            p.err_recover("expected pattern", recovery_set);
             return None;
         }
     };