diff --git a/tests/event-listeners/postmessage.spec.js b/tests/event-listeners/postmessage.spec.js
index 4901067..23390a8 100644
--- a/tests/event-listeners/postmessage.spec.js
+++ b/tests/event-listeners/postmessage.spec.js
@@ -64,16 +64,16 @@ describe('PostMessageListener', () => {
 	describe('PostMessageListener:_onCustomMessage', () => {
 		it('should verify that correct event has been dispatched on receiving data', () => {
 			unSetNewTabInfo();
-			let eventDetailData = JSON.stringify({
+			let eventDetailData = {
 				key: 'value'
-			}), data = PostMessageEventNamesEnum.CUSTOM + eventDetailData, eventSpy = jasmine.createSpy();
+			},
+			data = PostMessageEventNamesEnum.HANDSHAKE + JSON.stringify(eventDetailData),
+			eventSpy = jasmine.createSpy();
 
-			window.addEventListener('toggleElementDisabledAttribute', eventSpy);
-			PostMessageListener._onCustomMessage(data);
+			window.addEventListener('onCustomChildMessage', eventSpy);
+			PostMessageListener._onCustomMessage(data, PostMessageEventNamesEnum.HANDSHAKE);
 
-			expect(eventSpy).toHaveBeenCalledWith(jasmine.objectContaining({
-				detail: JSON.parse(eventDetailData)
-			}));
+			expect(eventSpy).toHaveBeenCalled();
 		});
 	});
 	describe('PostMessageListener:_onBeforeUnload', () => {
diff --git a/tests/parent.spec.js b/tests/parent.spec.js
index 854bdee..388daac 100644
--- a/tests/parent.spec.js
+++ b/tests/parent.spec.js
@@ -181,21 +181,38 @@ describe('Parent', () => {
 		it('should enable elements', () => {
 			spyOn(parent, 'enableElements');
 
-			parent.customEventUnListener({detail: {}});
+			parent.customEventUnListener({detail: {
+				type: PostMessageEventNamesEnum.HANDSHAKE
+			}});
 
 			expect(parent.enableElements).toHaveBeenCalled();
 		});
-		it('should call user-defined callback, if defined', () => {
+		it('should call handshake callback, if defined', () => {
 			let parent = new Parent({
 				onHandshakeCallback: function () {}
 			});
 
 			spyOn(parent, 'onHandshakeCallback');
 
-			parent.customEventUnListener({detail: {}});
+			parent.customEventUnListener({detail: {
+				type: PostMessageEventNamesEnum.HANDSHAKE
+			}});
 
 			expect(parent.onHandshakeCallback).toHaveBeenCalled();
 		});
+		it('should call user-defined callback, if defined', () => {
+			let parent = new Parent({
+				onChildCommunication: function () {}
+			});
+
+			spyOn(parent, 'onChildCommunication');
+
+			parent.customEventUnListener({detail: {
+				type: PostMessageEventNamesEnum.CUSTOM
+			}});
+
+			expect(parent.onChildCommunication).toHaveBeenCalled();
+		});
 	});
 
 	describe('method: addEventListeners', () => {