diff --git a/lib/index.node.ts b/lib/index.node.ts
index cd12b25fb..02d162ed6 100644
--- a/lib/index.node.ts
+++ b/lib/index.node.ts
@@ -15,7 +15,7 @@
  */
 import { NODE_CLIENT_ENGINE } from './utils/enums';
 import { Client, Config } from './shared_types';
-import { getOptimizelyInstance } from './client_factory';
+import { getOptimizelyInstance, OptimizelyFactoryConfig } from './client_factory';
 import { EventDispatcher } from './event_processor/event_dispatcher/event_dispatcher';
 import { NodeRequestHandler } from './utils/http_request_handler/request_handler.node';
 
@@ -26,9 +26,9 @@ import { NodeRequestHandler } from './utils/http_request_handler/request_handler
  *                           null on error
  */
 export const createInstance = function(config: Config): Client {
-  const nodeConfig = {
+  const nodeConfig: OptimizelyFactoryConfig = {
     ...config,
-    clientEnging: config.clientEngine || NODE_CLIENT_ENGINE,
+    clientEngine: config.clientEngine || NODE_CLIENT_ENGINE,
     requestHandler: new NodeRequestHandler(),
   }
 
diff --git a/lib/index.react_native.ts b/lib/index.react_native.ts
index a556290ba..c393261b7 100644
--- a/lib/index.react_native.ts
+++ b/lib/index.react_native.ts
@@ -17,7 +17,7 @@ import 'fast-text-encoding';
 import 'react-native-get-random-values';
 
 import { Client, Config } from './shared_types';
-import { getOptimizelyInstance } from './client_factory';
+import { getOptimizelyInstance, OptimizelyFactoryConfig } from './client_factory';
 import { REACT_NATIVE_JS_CLIENT_ENGINE } from './utils/enums';
 import { EventDispatcher } from './event_processor/event_dispatcher/event_dispatcher';
 import { BrowserRequestHandler } from './utils/http_request_handler/request_handler.browser';
@@ -29,7 +29,7 @@ import { BrowserRequestHandler } from './utils/http_request_handler/request_hand
  *                           null on error
  */
 export const createInstance = function(config: Config): Client {
-  const rnConfig = {
+  const rnConfig: OptimizelyFactoryConfig = {
     ...config,
     clientEngine: config.clientEngine || REACT_NATIVE_JS_CLIENT_ENGINE,
     requestHandler: new BrowserRequestHandler(),