--- a/js/src/jit-test/lib/syntax.js
+++ b/js/src/jit-test/lib/syntax.js
@@ -1237,16 +1237,30 @@ function test_syntax(postfixes, check_er
     test("async function A(a) { await X; ");
     test("async function A(a) { await X; } ");
     test("async function A(a) { await await ");
     test("async function A(a) { await await await ");
     test("async function A(a) { await await await X ");
     test("async function A(a) { await await await X; ");
     test("async function A(a) { await await await X; } ");
 
+    opts = { no_fun: true, no_eval: true, module: true };
+    test("export default async ", opts);
+    test("export default async function ", opts);
+    test("export default async function ( ", opts);
+    test("export default async function () ", opts);
+    test("export default async function (a ", opts);
+    test("export default async function (a) ", opts);
+    test("export default async function (a) { ", opts);
+    test("export default async function (a) {} ", opts);
+    test("export default async function (a) { await ", opts);
+    test("export default async function (a) { await X ", opts);
+    test("export default async function (a) { await X; ", opts);
+    test("export default async function (a) { await X; } ", opts);
+
     // async/await function expression
 
     test("(async ");
     test("(async function ");
     test("(async function A ");
     test("(async function A( ");
     test("(async function A() ");
     test("(async function A(a ");