diff --git a/js/src/jit-test/tests/modules/bug-1402649.js b/js/src/jit-test/tests/modules/bug-1402649.js
new file mode 100644
index 0000000000..2e5487210b
--- /dev/null
+++ b/js/src/jit-test/tests/modules/bug-1402649.js
@@ -0,0 +1,15 @@
+if (!('oomTest' in this))
+   quit();
+
+loadFile(`
+function parseAndEvaluate(source) {
+    let m = parseModule(source);
+    m.declarationInstantiation();
+}
+parseAndEvaluate("async function a() { await 2 + 3; }")
+`);
+function loadFile(lfVarx) {
+    oomTest(function() {
+        eval(lfVarx);
+    });
+}
diff --git a/js/src/tests/ecma_2017/AsyncFunctions/async-function-declaration-in-modules.js b/js/src/tests/ecma_2017/AsyncFunctions/async-function-declaration-in-modules.js
new file mode 100644
index 0000000000..41cc37bf33
--- /dev/null
+++ b/js/src/tests/ecma_2017/AsyncFunctions/async-function-declaration-in-modules.js
@@ -0,0 +1,13 @@
+// |reftest| module
+
+async function f() {
+    return "success";
+}
+
+var AsyncFunction = (async function(){}).constructor;
+
+assertEq(f instanceof AsyncFunction, true);
+
+f().then(v => {
+    reportCompare("success", v);
+});
diff --git a/js/src/tests/ecma_2018/AsyncGenerators/async-generator-declaration-in-modules.js b/js/src/tests/ecma_2018/AsyncGenerators/async-generator-declaration-in-modules.js
new file mode 100644
index 0000000000..6cac859579
--- /dev/null
+++ b/js/src/tests/ecma_2018/AsyncGenerators/async-generator-declaration-in-modules.js
@@ -0,0 +1,13 @@
+// |reftest| module skip-if(release_or_beta)
+
+async function* f() {
+    return "success";
+}
+
+var AsyncGenerator = (async function*(){}).constructor;
+
+assertEq(f instanceof AsyncGenerator, true);
+
+f().next().then(v => {
+    reportCompare("success", v.value);
+});
diff --git a/js/src/tests/ecma_2018/AsyncGenerators/browser.js b/js/src/tests/ecma_2018/AsyncGenerators/browser.js
new file mode 100644
index 0000000000..e69de29bb2
diff --git a/js/src/tests/ecma_2018/AsyncGenerators/shell.js b/js/src/tests/ecma_2018/AsyncGenerators/shell.js
new file mode 100644
index 0000000000..e69de29bb2
diff --git a/js/src/tests/ecma_2018/browser.js b/js/src/tests/ecma_2018/browser.js
new file mode 100644
index 0000000000..e69de29bb2
diff --git a/js/src/tests/ecma_2018/shell.js b/js/src/tests/ecma_2018/shell.js
new file mode 100644
index 0000000000..e69de29bb2