diff --git a/test/built-ins/AsyncFunction/proto-from-ctor-realm.js b/test/built-ins/AsyncFunction/proto-from-ctor-realm.js
new file mode 100644
index 0000000000..566266e593
--- /dev/null
+++ b/test/built-ins/AsyncFunction/proto-from-ctor-realm.js
@@ -0,0 +1,62 @@
+// Copyright (C) 2019 Alexey Shvayka. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-async-function-constructor-arguments
+description: Default [[Prototype]] value derived from realm of the NewTarget.
+info: |
+  AsyncFunction ( p1, p2, … , pn, body )
+
+  ...
+  3. Return CreateDynamicFunction(C, NewTarget, "async", args).
+
+  Runtime Semantics: CreateDynamicFunction ( constructor, newTarget, kind, args )
+
+  ...
+  9. Else if kind is "async", then
+    ...
+    c. Let fallbackProto be "%AsyncFunction.prototype%".
+  ...
+  18. Let proto be ? GetPrototypeFromConstructor(newTarget, fallbackProto).
+  ...
+
+  GetPrototypeFromConstructor ( constructor, intrinsicDefaultProto )
+
+  ...
+  3. Let proto be ? Get(constructor, "prototype").
+  4. If Type(proto) is not Object, then
+    a. Let realm be ? GetFunctionRealm(constructor).
+    b. Set proto to realm's intrinsic object named intrinsicDefaultProto.
+  5. Return proto.
+features: [async-functions, cross-realm, Reflect, Symbol]
+---*/
+
+var AsyncFunction = Object.getPrototypeOf(async function() {}).constructor;
+var other = $262.createRealm().global;
+var OtherAsyncFunction = Object.getPrototypeOf(other.eval('(0, async function() {})')).constructor;
+var newTarget = new other.Function();
+var fn;
+
+newTarget.prototype = undefined;
+fn = Reflect.construct(AsyncFunction, [], newTarget);
+assert.sameValue(Object.getPrototypeOf(fn), OtherAsyncFunction.prototype, 'newTarget.prototype is undefined');
+
+newTarget.prototype = null;
+fn = Reflect.construct(AsyncFunction, [], newTarget);
+assert.sameValue(Object.getPrototypeOf(fn), OtherAsyncFunction.prototype, 'newTarget.prototype is null');
+
+newTarget.prototype = true;
+fn = Reflect.construct(AsyncFunction, [], newTarget);
+assert.sameValue(Object.getPrototypeOf(fn), OtherAsyncFunction.prototype, 'newTarget.prototype is a Boolean');
+
+newTarget.prototype = '';
+fn = Reflect.construct(AsyncFunction, [], newTarget);
+assert.sameValue(Object.getPrototypeOf(fn), OtherAsyncFunction.prototype, 'newTarget.prototype is a String');
+
+newTarget.prototype = Symbol();
+fn = Reflect.construct(AsyncFunction, [], newTarget);
+assert.sameValue(Object.getPrototypeOf(fn), OtherAsyncFunction.prototype, 'newTarget.prototype is a Symbol');
+
+newTarget.prototype = 1;
+fn = Reflect.construct(AsyncFunction, [], newTarget);
+assert.sameValue(Object.getPrototypeOf(fn), OtherAsyncFunction.prototype, 'newTarget.prototype is a Number');
diff --git a/test/built-ins/AsyncGeneratorFunction/proto-from-ctor-realm.js b/test/built-ins/AsyncGeneratorFunction/proto-from-ctor-realm.js
new file mode 100644
index 0000000000..7b47b091e7
--- /dev/null
+++ b/test/built-ins/AsyncGeneratorFunction/proto-from-ctor-realm.js
@@ -0,0 +1,63 @@
+// Copyright (C) 2019 Alexey Shvayka. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-asyncgeneratorfunction
+description: Default [[Prototype]] value derived from realm of the NewTarget.
+info: |
+  AsyncGeneratorFunction ( p1, p2, … , pn, body )
+
+  ...
+  3. Return ? CreateDynamicFunction(C, NewTarget, "async generator", args).
+
+  Runtime Semantics: CreateDynamicFunction ( constructor, newTarget, kind, args )
+
+  ...
+  10. Else,
+    a. Assert: kind is "async generator".
+    ...
+    d. Let fallbackProto be "%AsyncGenerator%".
+  ...
+  18. Let proto be ? GetPrototypeFromConstructor(newTarget, fallbackProto).
+  ...
+
+  GetPrototypeFromConstructor ( constructor, intrinsicDefaultProto )
+
+  ...
+  3. Let proto be ? Get(constructor, "prototype").
+  4. If Type(proto) is not Object, then
+    a. Let realm be ? GetFunctionRealm(constructor).
+    b. Set proto to realm's intrinsic object named intrinsicDefaultProto.
+  5. Return proto.
+features: [async-iteration, cross-realm, Reflect, Symbol]
+---*/
+
+var AsyncGeneratorFunction = Object.getPrototypeOf(async function* () {}).constructor;
+var other = $262.createRealm().global;
+var OtherAsyncGeneratorFunction = Object.getPrototypeOf(other.eval('(0, async function* () {})')).constructor;
+var newTarget = new other.Function();
+var fn;
+
+newTarget.prototype = undefined;
+fn = Reflect.construct(AsyncGeneratorFunction, [], newTarget);
+assert.sameValue(Object.getPrototypeOf(fn), OtherAsyncGeneratorFunction.prototype, 'newTarget.prototype is undefined');
+
+newTarget.prototype = null;
+fn = Reflect.construct(AsyncGeneratorFunction, [], newTarget);
+assert.sameValue(Object.getPrototypeOf(fn), OtherAsyncGeneratorFunction.prototype, 'newTarget.prototype is null');
+
+newTarget.prototype = true;
+fn = Reflect.construct(AsyncGeneratorFunction, [], newTarget);
+assert.sameValue(Object.getPrototypeOf(fn), OtherAsyncGeneratorFunction.prototype, 'newTarget.prototype is a Boolean');
+
+newTarget.prototype = '';
+fn = Reflect.construct(AsyncGeneratorFunction, [], newTarget);
+assert.sameValue(Object.getPrototypeOf(fn), OtherAsyncGeneratorFunction.prototype, 'newTarget.prototype is a String');
+
+newTarget.prototype = Symbol();
+fn = Reflect.construct(AsyncGeneratorFunction, [], newTarget);
+assert.sameValue(Object.getPrototypeOf(fn), OtherAsyncGeneratorFunction.prototype, 'newTarget.prototype is a Symbol');
+
+newTarget.prototype = 1;
+fn = Reflect.construct(AsyncGeneratorFunction, [], newTarget);
+assert.sameValue(Object.getPrototypeOf(fn), OtherAsyncGeneratorFunction.prototype, 'newTarget.prototype is a Number');