diff --git a/dist/index.js b/dist/index.js
index 7a4be24d..5495c423 100644
--- a/dist/index.js
+++ b/dist/index.js
@@ -153,7 +153,7 @@ var RandomGeneratorUtils = function () {
     _createClass(RandomGeneratorUtils, null, [{
         key: "getRandomFloat",
         value: function getRandomFloat(min, max) {
-            return RandomGeneratorUtils.randomGenerator.floating({
+            return RandomGeneratorUtils.getRandomGenerator().floating({
                 min: min,
                 max: max,
                 fixed: 7
@@ -171,7 +171,7 @@ var RandomGeneratorUtils = function () {
     }, {
         key: "getRandomInteger",
         value: function getRandomInteger(min, max) {
-            return RandomGeneratorUtils.randomGenerator.integer({
+            return RandomGeneratorUtils.getRandomGenerator().integer({
                 min: min,
                 max: max
             });
@@ -195,9 +195,9 @@ var RandomGeneratorUtils = function () {
             return "" + prefix + Utils_1.Utils.decToHex(RandomGeneratorUtils.getRandomInteger(rangeMinInteger, rangeMaxInteger)).substr(0, length);
         }
     }, {
-        key: "setRandomGeneratorSeed",
-        value: function setRandomGeneratorSeed(randomGeneratorSeed) {
-            RandomGeneratorUtils.randomGenerator = new chance_1.Chance(randomGeneratorSeed);
+        key: "setRandomGenerator",
+        value: function setRandomGenerator(randomGenerator) {
+            RandomGeneratorUtils.randomGenerator = randomGenerator;
         }
     }]);
 
@@ -944,6 +944,7 @@ if (!global._babelPolyfill) {
     __webpack_require__(114);
 }
 var ServiceIdentifiers_1 = __webpack_require__(1);
+var chance_1 = __webpack_require__(115);
 var InversifyContainerFacade_1 = __webpack_require__(41);
 var JavaScriptObfuscatorCLI_1 = __webpack_require__(40);
 var RandomGeneratorUtils_1 = __webpack_require__(2);
@@ -961,7 +962,7 @@ var JavaScriptObfuscator = function () {
             var inversifyContainerFacade = new InversifyContainerFacade_1.InversifyContainerFacade(inputOptions);
             var options = inversifyContainerFacade.get(ServiceIdentifiers_1.ServiceIdentifiers.IOptions);
             if (options.seed !== 0) {
-                RandomGeneratorUtils_1.RandomGeneratorUtils.setRandomGeneratorSeed(options.seed);
+                RandomGeneratorUtils_1.RandomGeneratorUtils.setRandomGenerator(new chance_1.Chance(options.seed));
             }
             var javaScriptObfuscator = inversifyContainerFacade.get(ServiceIdentifiers_1.ServiceIdentifiers.IJavaScriptObfuscator);
             return javaScriptObfuscator.obfuscate(sourceCode);
@@ -1312,12 +1313,12 @@ var CryptUtils = function () {
     }
 
     _createClass(CryptUtils, null, [{
-        key: 'btoa',
+        key: "btoa",
         value: function btoa(string) {
             var chars = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=';
             var output = '';
             string = encodeURIComponent(string).replace(/%([0-9A-F]{2})/g, function (match, p1) {
-                return String.fromCharCode(parseInt('' + Utils_1.Utils.hexadecimalPrefix + p1));
+                return String.fromCharCode(parseInt("" + Utils_1.Utils.hexadecimalPrefix + p1));
             });
             for (var block, charCode, idx = 0, map = chars; string.charAt(idx | 0) || (map = '=', idx % 1); output += map.charAt(63 & block >> 8 - idx % 1 * 8)) {
                 charCode = string.charCodeAt(idx += 3 / 4);
@@ -1329,7 +1330,7 @@ var CryptUtils = function () {
             return output;
         }
     }, {
-        key: 'hideString',
+        key: "hideString",
         value: function hideString(str, length) {
             var escapeRegExp = function escapeRegExp(s) {
                 return s.replace(/[-\/\\^$*+?.()|[\]{}]/g, '\\$&');
@@ -1347,18 +1348,18 @@ var CryptUtils = function () {
                 }
                 return result;
             };
-            var randomString = RandomGeneratorUtils_1.RandomGeneratorUtils.randomGenerator.string({
+            var randomString = RandomGeneratorUtils_1.RandomGeneratorUtils.getRandomGenerator().string({
                 length: length,
                 pool: RandomGeneratorUtils_1.RandomGeneratorUtils.randomGeneratorPool
             });
             var randomStringDiff = randomString.replace(new RegExp('[' + escapeRegExp(str) + ']', 'g'), '');
             var randomStringDiffArray = randomStringDiff.split('');
-            RandomGeneratorUtils_1.RandomGeneratorUtils.randomGenerator.shuffle(randomStringDiffArray);
+            RandomGeneratorUtils_1.RandomGeneratorUtils.getRandomGenerator().shuffle(randomStringDiffArray);
             randomStringDiff = randomStringDiffArray.join('');
             return [randomMerge(str, randomStringDiff), randomStringDiff];
         }
     }, {
-        key: 'rc4',
+        key: "rc4",
         value: function rc4(string, key) {
             var s = [],
                 j = 0,
diff --git a/src/JavaScriptObfuscator.ts b/src/JavaScriptObfuscator.ts
index 0f0179d4..1573d541 100644
--- a/src/JavaScriptObfuscator.ts
+++ b/src/JavaScriptObfuscator.ts
@@ -6,6 +6,8 @@ if (!(<any>global)._babelPolyfill) {
 
 import { ServiceIdentifiers } from './container/ServiceIdentifiers';
 
+import { Chance } from 'chance';
+
 import { TInputOptions } from './types/options/TInputOptions';
 
 import { IInversifyContainerFacade } from './interfaces/container/IInversifyContainerFacade';
@@ -28,7 +30,7 @@ export class JavaScriptObfuscator {
         const options: IOptions = inversifyContainerFacade.get<IOptions>(ServiceIdentifiers.IOptions);
 
         if (options.seed !== 0) {
-            RandomGeneratorUtils.setRandomGeneratorSeed(options.seed);
+            RandomGeneratorUtils.setRandomGenerator(new Chance(options.seed));
         }
 
         const javaScriptObfuscator: IJavaScriptObfuscator = inversifyContainerFacade
diff --git a/src/utils/CryptUtils.ts b/src/utils/CryptUtils.ts
index 870cf8af..d2ce86f3 100644
--- a/src/utils/CryptUtils.ts
+++ b/src/utils/CryptUtils.ts
@@ -58,7 +58,7 @@ export class CryptUtils {
             return result;
         };
 
-        const randomString: string = RandomGeneratorUtils.randomGenerator.string({
+        const randomString: string = RandomGeneratorUtils.getRandomGenerator().string({
             length: length,
             pool: RandomGeneratorUtils.randomGeneratorPool
         });
@@ -69,7 +69,7 @@ export class CryptUtils {
 
         const randomStringDiffArray: string[] = randomStringDiff.split('');
 
-        RandomGeneratorUtils.randomGenerator.shuffle(randomStringDiffArray);
+        RandomGeneratorUtils.getRandomGenerator().shuffle(randomStringDiffArray);
         randomStringDiff = randomStringDiffArray.join('');
 
         return [randomMerge(str, randomStringDiff), randomStringDiff];
diff --git a/src/utils/RandomGeneratorUtils.ts b/src/utils/RandomGeneratorUtils.ts
index daac331e..4cf75da2 100644
--- a/src/utils/RandomGeneratorUtils.ts
+++ b/src/utils/RandomGeneratorUtils.ts
@@ -16,7 +16,7 @@ export class RandomGeneratorUtils {
     /**
      * @type {Chance.Chance | Chance.SeededChance}
      */
-    public static randomGenerator: Chance.Chance | Chance.SeededChance = new Chance();
+    private static randomGenerator: Chance.Chance | Chance.SeededChance = new Chance();
 
     /**
      * @param min
@@ -24,7 +24,7 @@ export class RandomGeneratorUtils {
      * @returns {number}
      */
     public static getRandomFloat (min: number, max: number): number {
-        return RandomGeneratorUtils.randomGenerator.floating({
+        return RandomGeneratorUtils.getRandomGenerator().floating({
             min: min,
             max: max,
             fixed: 7
@@ -50,7 +50,7 @@ export class RandomGeneratorUtils {
      * @returns {number}
      */
     public static getRandomInteger (min: number, max: number): number {
-        return RandomGeneratorUtils.randomGenerator.integer({
+        return RandomGeneratorUtils.getRandomGenerator().integer({
             min: min,
             max: max
         });
@@ -83,9 +83,9 @@ export class RandomGeneratorUtils {
     }
 
     /**
-     * @param randomGeneratorSeed
+     * @param randomGenerator
      */
-    public static setRandomGeneratorSeed (randomGeneratorSeed: number): void {
-        RandomGeneratorUtils.randomGenerator = new Chance(randomGeneratorSeed);
+    public static setRandomGenerator (randomGenerator: Chance.Chance | Chance.SeededChance): void {
+        RandomGeneratorUtils.randomGenerator = randomGenerator;
     }
 }
diff --git a/test/functional-tests/JavaScriptObfuscator.spec.ts b/test/functional-tests/JavaScriptObfuscator.spec.ts
index f51383f9..67f63184 100644
--- a/test/functional-tests/JavaScriptObfuscator.spec.ts
+++ b/test/functional-tests/JavaScriptObfuscator.spec.ts
@@ -1,14 +1,21 @@
 import { assert } from 'chai';
 
+import { Chance } from 'chance';
+
 import { IObfuscationResult } from '../../src/interfaces/IObfuscationResult';
 
 import { JavaScriptObfuscator } from '../../src/JavaScriptObfuscator';
 
 import { NO_CUSTOM_NODES_PRESET } from '../../src/preset-options/NoCustomNodesPreset';
 import { readFileAsString } from '../helpers/readFileAsString';
+import { RandomGeneratorUtils } from '../../src/utils/RandomGeneratorUtils';
 
 describe('JavaScriptObfuscator', () => {
     describe('obfuscate (sourceCode: string, customOptions?: IObfuscatorOptions): IObfuscationResult', () => {
+        beforeEach(() => {
+            RandomGeneratorUtils.setRandomGenerator(new Chance());
+        });
+
         describe('if `sourceMap` option is `false`', () => {
             it('should returns object with obfuscated code and empty source map', () => {
                 let obfuscationResult: IObfuscationResult = JavaScriptObfuscator.obfuscate(
@@ -171,5 +178,9 @@ describe('JavaScriptObfuscator', () => {
             assert.notEqual(obfuscationResult1.getObfuscatedCode(), obfuscationResult2.getObfuscatedCode());
             assert.notEqual(obfuscationResult3.getObfuscatedCode(), obfuscationResult4.getObfuscatedCode());
         });
+
+        afterEach(() => {
+            RandomGeneratorUtils.setRandomGenerator(new Chance());
+        });
     });
 });
diff --git a/test/functional-tests/node-transformers/node-control-flow-transformers/control-flow-replacers/BinaryExpressionControlFlowReplacer.spec.ts b/test/functional-tests/node-transformers/node-control-flow-transformers/control-flow-replacers/BinaryExpressionControlFlowReplacer.spec.ts
index 3617170c..2c9e02a6 100644
--- a/test/functional-tests/node-transformers/node-control-flow-transformers/control-flow-replacers/BinaryExpressionControlFlowReplacer.spec.ts
+++ b/test/functional-tests/node-transformers/node-control-flow-transformers/control-flow-replacers/BinaryExpressionControlFlowReplacer.spec.ts
@@ -31,7 +31,9 @@ describe('BinaryExpressionControlFlowReplacer', () => {
 
         describe('variant #2 - multiple binary expressions with threshold = 1', () => {
             it('should replace binary expression node by call to control flow storage node', () => {
-                const samplesCount: number = 50;
+                const samplesCount: number = 100;
+                const expectedValue: number = 0.5;
+                const delta: number = 0.08;
 
                 let equalsValue: number = 0;
 
@@ -66,7 +68,7 @@ describe('BinaryExpressionControlFlowReplacer', () => {
                     }
                 }
 
-                assert.closeTo(equalsValue / samplesCount, 0.5, 0.05);
+                assert.closeTo(equalsValue / samplesCount, expectedValue, delta);
             });
         });
     });