diff --git a/packages/optimizely-sdk/lib/core/decision_service/index.tests.js b/packages/optimizely-sdk/lib/core/decision_service/index.tests.js
index 6571364d1..0f5b20552 100644
--- a/packages/optimizely-sdk/lib/core/decision_service/index.tests.js
+++ b/packages/optimizely-sdk/lib/core/decision_service/index.tests.js
@@ -32,7 +32,7 @@ import AudienceEvaluator from '../audience_evaluator';
 import errorHandler from '../../plugins/error_handler';
 import eventBuilder from '../../core/event_builder/index.js';
 import eventDispatcher from '../../plugins/event_dispatcher/index.node';
-import jsonSchemaValidator from '../../utils/json_schema_validator';
+import * as jsonSchemaValidator from '../../utils/json_schema_validator';
 import {
   getTestProjectConfig,
   getTestProjectConfigWithFeatures,
diff --git a/packages/optimizely-sdk/lib/core/project_config/project_config_manager.tests.js b/packages/optimizely-sdk/lib/core/project_config/project_config_manager.tests.js
index de38044ea..e43b95fc5 100644
--- a/packages/optimizely-sdk/lib/core/project_config/project_config_manager.tests.js
+++ b/packages/optimizely-sdk/lib/core/project_config/project_config_manager.tests.js
@@ -25,7 +25,7 @@ import { ERROR_MESSAGES, LOG_MESSAGES } from '../../utils/enums';
 import testData from '../../tests/test_data';
 import * as optimizelyConfig from '../optimizely_config/index';
 import projectConfigManager from './project_config_manager';
-import jsonSchemaValidator from '../../utils/json_schema_validator';
+import * as jsonSchemaValidator from '../../utils/json_schema_validator';
 
 describe('lib/core/project_config/project_config_manager', function() {
   var globalStubErrorHandler;
diff --git a/packages/optimizely-sdk/lib/core/project_config/project_config_schema.js b/packages/optimizely-sdk/lib/core/project_config/project_config_schema.ts
similarity index 97%
rename from packages/optimizely-sdk/lib/core/project_config/project_config_schema.js
rename to packages/optimizely-sdk/lib/core/project_config/project_config_schema.ts
index d04959b0d..e21830b89 100644
--- a/packages/optimizely-sdk/lib/core/project_config/project_config_schema.js
+++ b/packages/optimizely-sdk/lib/core/project_config/project_config_schema.ts
@@ -17,7 +17,9 @@
 /**
  * Project Config JSON Schema file used to validate the project json datafile
  */
-export var schema = {
+ import { JSONSchema4 } from 'json-schema';
+
+ var schemaDefinition = {
   $schema: 'http://json-schema.org/draft-04/schema#',
   type: 'object',
   properties: {
@@ -276,4 +278,6 @@ export var schema = {
   },
 };
 
-export default schema;
+const schema = schemaDefinition as JSONSchema4
+
+export default schema
diff --git a/packages/optimizely-sdk/lib/optimizely/index.tests.js b/packages/optimizely-sdk/lib/optimizely/index.tests.js
index 777d4c505..003685832 100644
--- a/packages/optimizely-sdk/lib/optimizely/index.tests.js
+++ b/packages/optimizely-sdk/lib/optimizely/index.tests.js
@@ -31,7 +31,7 @@ import errorHandler from '../plugins/error_handler';
 import fns from '../utils/fns';
 import logger from '../plugins/logger';
 import decisionService from '../core/decision_service';
-import jsonSchemaValidator from '../utils/json_schema_validator';
+import * as jsonSchemaValidator from '../utils/json_schema_validator';
 import projectConfig from '../core/project_config';
 import testData from '../tests/test_data';
 
diff --git a/packages/optimizely-sdk/lib/utils/json_schema_validator/index.js b/packages/optimizely-sdk/lib/utils/json_schema_validator/index.ts
similarity index 74%
rename from packages/optimizely-sdk/lib/utils/json_schema_validator/index.js
rename to packages/optimizely-sdk/lib/utils/json_schema_validator/index.ts
index 3f21978de..a30df70a8 100644
--- a/packages/optimizely-sdk/lib/utils/json_schema_validator/index.js
+++ b/packages/optimizely-sdk/lib/utils/json_schema_validator/index.ts
@@ -17,21 +17,21 @@ import { sprintf } from '@optimizely/js-sdk-utils';
 import { validate as jsonSchemaValidator } from 'json-schema';
 
 import { ERROR_MESSAGES } from '../enums';
-import projectConfigSchema from '../../core/project_config/project_config_schema';
+import schema from '../../core/project_config/project_config_schema';
 
-var MODULE_NAME = 'JSON_SCHEMA_VALIDATOR';
+const MODULE_NAME = 'JSON_SCHEMA_VALIDATOR';
 
 /**
  * Validate the given json object against the specified schema
- * @param  {Object} jsonObject The object to validate against the schema
- * @return {Boolean}           True if the given object is valid
+ * @param  {unknown} jsonObject The object to validate against the schema
+ * @return {boolean}            true if the given object is valid
  */
-export var validate = function(jsonObject) {
+export function validate(jsonObject: unknown): boolean {
   if (!jsonObject) {
     throw new Error(sprintf(ERROR_MESSAGES.NO_JSON_PROVIDED, MODULE_NAME));
   }
 
-  var result = jsonSchemaValidator(jsonObject, projectConfigSchema);
+  const result = jsonSchemaValidator(jsonObject as {}, schema);
   if (result.valid) {
     return true;
   } else {
@@ -42,8 +42,4 @@ export var validate = function(jsonObject) {
     }
     throw new Error(sprintf(ERROR_MESSAGES.INVALID_JSON, MODULE_NAME));
   }
-};
-
-export default {
-  validate: validate,
-};
+}