diff --git a/src/ImmutableStore.es6.js b/src/ImmutableStore.es6.js
index <HASH>..<HASH> 100644
--- a/src/ImmutableStore.es6.js
+++ b/src/ImmutableStore.es6.js
@@ -20,7 +20,6 @@ var Immutable = require('immutable');
 var ObjectOrientedStore = require('./ObjectOrientedStore.es6');
 
 const IN_PRODUCTION = process.env.NODE_ENV === 'production';
-const CHECK_IMMUTABILITY = !!process.env.CHECK_IMMUTABILITY;
 
 /**
  * A Flux Store which is strict on Immutability
@@ -51,7 +50,7 @@ class ImmutableStore extends ObjectOrientedStore {
 	constructor (options) {
 		// If we are in production, then lets skip adding
 		// the immutability checks for performance sake.
-		if (!CHECK_IMMUTABILITY && IN_PRODUCTION) {
+		if (IN_PRODUCTION) {
 			super(options);
 			return;
 		}
Removed env for adding immutability check