diff --git a/.travis.yml b/.travis.yml
index 8f5e52c523..240018726d 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,6 +1,6 @@
 language: node_js
 node_js:
-  - "node"
+  - "11.10.1"
 install:
   - npm i -g npm@5.8.0
   - npm ci
diff --git a/index.d.ts b/index.d.ts
index 2059493512..45463b7e76 100644
--- a/index.d.ts
+++ b/index.d.ts
@@ -211,7 +211,9 @@ export interface Store<S = any, A extends Action = AnyAction> {
   replaceReducer(nextReducer: Reducer<S, A>): void
 }
 
-export type DeepPartial<T> = { [K in keyof T]?: DeepPartial<T[K]> }
+export type DeepPartial<T> = {
+  [K in keyof T]?: T[K] extends object ? DeepPartial<T[K]> : T[K]
+}
 
 /**
  * A store creator is a function that creates a Redux store. Like with