diff --git a/client/lib/domains/dns/test/index.js b/client/lib/domains/dns/test/index-test.js
similarity index 100%
rename from client/lib/domains/dns/test/index.js
rename to client/lib/domains/dns/test/index-test.js
diff --git a/client/lib/domains/dns/test/reducer-test.js b/client/lib/domains/dns/test/reducer-test.js
index d60e1444878a97..fc3ba67c8fbb8c 100644
--- a/client/lib/domains/dns/test/reducer-test.js
+++ b/client/lib/domains/dns/test/reducer-test.js
@@ -1,6 +1,7 @@
 /**
  * External dependencies
  */
+import deepFreeze from 'deep-freeze';
 import { expect } from 'chai';
 import pick from 'lodash/object/pick';
 
@@ -13,11 +14,11 @@ import { reducer } from '../reducer';
 
 describe( 'Domains: DNS reducer', () => {
 	it( 'should return the same state when no matching record passed in the delete action', () => {
-		const state = {
+		const state = deepFreeze( {
 				[ DOMAIN_NAME ]: {
 					records: [ RECORD_A ]
 				}
-			},
+			} ),
 			payload = {
 				action: {
 					type: ActionTypes.DNS_DELETE_COMPLETED,
@@ -32,11 +33,11 @@ describe( 'Domains: DNS reducer', () => {
 	} );
 
 	it( 'should return state without record passed in the delete action', () => {
-		const state = {
+		const state = deepFreeze( {
 				[ DOMAIN_NAME ]: {
 					records: [ RECORD_TXT ]
 				}
-			},
+			} ),
 			payload = {
 				action: {
 					type: ActionTypes.DNS_DELETE_COMPLETED,
@@ -52,11 +53,11 @@ describe( 'Domains: DNS reducer', () => {
 
 	it( 'should return state without record (having no id) passed in the delete action', () => {
 		const RECORD_TXT_WITHOUT_ID = pick( RECORD_TXT, [ 'data', 'name', 'type' ] ),
-			state = {
+			state = deepFreeze( {
 				[ DOMAIN_NAME ]: {
 					records: [ RECORD_TXT_WITHOUT_ID ]
 				}
-			},
+			} ),
 			payload = {
 				action: {
 					type: ActionTypes.DNS_DELETE_COMPLETED,
diff --git a/client/lib/domains/email-forwarding/test/reducer-test.js b/client/lib/domains/email-forwarding/test/reducer-test.js
index 233e2d3aef282b..42e5089937ed74 100644
--- a/client/lib/domains/email-forwarding/test/reducer-test.js
+++ b/client/lib/domains/email-forwarding/test/reducer-test.js
@@ -1,6 +1,7 @@
 /**
  * External dependencies
  */
+import deepFreeze from 'deep-freeze';
 import { expect } from 'chai';
 
 /**
@@ -12,11 +13,11 @@ import { reducer } from './../reducer';
 
 describe( 'Domains: Email Forwarding Reducer', () => {
 	it( 'should return the same state when no matching record passed in the delete complete action', () => {
-		const state = {
+		const state = deepFreeze( {
 				[ DOMAIN_NAME ]: {
 					list: EMAIL_FORWARDS
 				}
-			},
+			} ),
 			payload = {
 				action: {
 					type: ActionTypes.EMAIL_FORWARDING_DELETE_COMPLETED,
@@ -35,11 +36,11 @@ describe( 'Domains: Email Forwarding Reducer', () => {
 	} );
 
 	it( 'should return state without record passed in the delete completed action', () => {
-		const state = {
+		const state = deepFreeze( {
 				[ DOMAIN_NAME ]: {
 					list: EMAIL_FORWARDS
 				}
-			},
+			} ),
 			payload = {
 				action: {
 					type: ActionTypes.EMAIL_FORWARDING_DELETE_COMPLETED,
diff --git a/client/lib/purchases/stored-cards/test/assembler-test.js b/client/lib/purchases/stored-cards/test/assembler-test.js
index 52751e13f75cca..5e8ec753fa1580 100644
--- a/client/lib/purchases/stored-cards/test/assembler-test.js
+++ b/client/lib/purchases/stored-cards/test/assembler-test.js
@@ -7,7 +7,7 @@ import { expect } from 'chai';
  * Internal dependencies
  */
 import { createStoredCardsArray } from '../assembler.js';
-import { STORED_CARDS_FROM_API, STORED_CARDS } from './constants';
+import { STORED_CARDS_FROM_API, STORED_CARDS } from './data';
 
 describe( 'Stored Cards assembler', () => {
 	it( 'should be a function', () => {
diff --git a/client/lib/purchases/stored-cards/test/constants.js b/client/lib/purchases/stored-cards/test/data/index.js
similarity index 100%
rename from client/lib/purchases/stored-cards/test/constants.js
rename to client/lib/purchases/stored-cards/test/data/index.js
diff --git a/client/lib/purchases/stored-cards/test/store-test.js b/client/lib/purchases/stored-cards/test/store-test.js
index e2811079ce185d..687f7386b9a741 100644
--- a/client/lib/purchases/stored-cards/test/store-test.js
+++ b/client/lib/purchases/stored-cards/test/store-test.js
@@ -11,7 +11,7 @@ import rest from 'lodash/array/rest';
  */
 import { action as ActionTypes } from 'lib/upgrades/constants';
 import Dispatcher from 'dispatcher';
-import { STORED_CARDS_FROM_API, STORED_CARDS } from './constants';
+import { STORED_CARDS_FROM_API, STORED_CARDS } from './data';
 import StoredCardsStore from './../store';
 
 describe( 'Stored Cards Store', () => {
diff --git a/package.json b/package.json
index a2795bf1c17730..d9f75aa565e6ad 100644
--- a/package.json
+++ b/package.json
@@ -115,6 +115,7 @@
     "blanket": "1.1.6",
     "chai": "2.0.0",
     "chai-immutable": "^1.4.0",
+    "deep-freeze": "0.0.1",
     "enzyme": "1.1.0",
     "esformatter": "0.7.3",
     "esformatter-braces": "1.2.1",