diff --git a/keyserver/flow-typed/npm/redux_v4.x.x.js b/keyserver/flow-typed/npm/redux_v4.x.x.js
--- a/keyserver/flow-typed/npm/redux_v4.x.x.js
+++ b/keyserver/flow-typed/npm/redux_v4.x.x.js
@@ -1,5 +1,5 @@
-// flow-typed signature: cf5a251230b87bfccb7000d63228c501
-// flow-typed version: 7735fcd9c6/redux_v4.x.x/flow_>=v0.134.x
+// flow-typed signature: f42950aebee3189b48dae0d4697c6776
+// flow-typed version: 0e28de5e8a/redux_v4.x.x/flow_>=v0.201.x
 
 declare module 'redux' {
   /*
@@ -14,7 +14,7 @@
 
   declare export type DispatchAPI<A> = (action: A) => A;
 
-  declare export type Dispatch<A: { +type: *, ... }> = DispatchAPI<A>;
+  declare export type Dispatch<A: { type: any, ... }> = DispatchAPI<A>;
 
   declare export type MiddlewareAPI<S, A, D = Dispatch<A>> = {
     dispatch: D,
@@ -31,12 +31,7 @@
     ...
   };
 
-  declare export type Reducer<S, A> = (state: S | void, action: A) => S;
-
-  declare export type CombinedReducer<S, A> = (
-    state: ($Shape<S> & {...}) | void,
-    action: A
-  ) => S;
+  declare export type Reducer<S, A> = (state: S, action: A) => S;
 
   declare export type Middleware<S, A, D = Dispatch<A>> = (
     api: MiddlewareAPI<S, A, D>
@@ -66,6 +61,16 @@
     enhancer?: StoreEnhancer<S, A, D>
   ): Store<S, A, D>;
 
+  declare export function legacy_createStore<S, A, D>(
+    reducer: Reducer<S, A>,
+    enhancer?: StoreEnhancer<S, A, D>
+  ): Store<S, A, D>;
+  declare export function legacy_createStore<S, A, D>(
+    reducer: Reducer<S, A>,
+    preloadedState?: S,
+    enhancer?: StoreEnhancer<S, A, D>
+  ): Store<S, A, D>;
+
   declare export function applyMiddleware<S, A, D>(
     ...middlewares: Array<Middleware<S, A, D>>
   ): StoreEnhancer<S, A, D>;
@@ -91,9 +96,9 @@
     dispatch: D
   ): C;
 
-  declare export function combineReducers<O: {...}, A>(
-    reducers: O
-  ): CombinedReducer<$ObjMap<O, <S>(r: Reducer<S, any>) => S>, A>;
+  declare export function combineReducers<RootState: {...}, A>(
+    reducers: $ObjMap<RootState, <V>(V) => Reducer<V, A>>,
+  ): Reducer<RootState, A>;
 
   declare export var compose: $Compose;
 }
diff --git a/lib/flow-typed/npm/redux_v4.x.x.js b/lib/flow-typed/npm/redux_v4.x.x.js
--- a/lib/flow-typed/npm/redux_v4.x.x.js
+++ b/lib/flow-typed/npm/redux_v4.x.x.js
@@ -1,5 +1,5 @@
-// flow-typed signature: cf5a251230b87bfccb7000d63228c501
-// flow-typed version: 7735fcd9c6/redux_v4.x.x/flow_>=v0.134.x
+// flow-typed signature: f42950aebee3189b48dae0d4697c6776
+// flow-typed version: 0e28de5e8a/redux_v4.x.x/flow_>=v0.201.x
 
 declare module 'redux' {
   /*
@@ -14,7 +14,7 @@
 
   declare export type DispatchAPI<A> = (action: A) => A;
 
-  declare export type Dispatch<A: { +type: *, ... }> = DispatchAPI<A>;
+  declare export type Dispatch<A: { type: any, ... }> = DispatchAPI<A>;
 
   declare export type MiddlewareAPI<S, A, D = Dispatch<A>> = {
     dispatch: D,
@@ -31,12 +31,7 @@
     ...
   };
 
-  declare export type Reducer<S, A> = (state: S | void, action: A) => S;
-
-  declare export type CombinedReducer<S, A> = (
-    state: ($Shape<S> & {...}) | void,
-    action: A
-  ) => S;
+  declare export type Reducer<S, A> = (state: S, action: A) => S;
 
   declare export type Middleware<S, A, D = Dispatch<A>> = (
     api: MiddlewareAPI<S, A, D>
@@ -66,6 +61,16 @@
     enhancer?: StoreEnhancer<S, A, D>
   ): Store<S, A, D>;
 
+  declare export function legacy_createStore<S, A, D>(
+    reducer: Reducer<S, A>,
+    enhancer?: StoreEnhancer<S, A, D>
+  ): Store<S, A, D>;
+  declare export function legacy_createStore<S, A, D>(
+    reducer: Reducer<S, A>,
+    preloadedState?: S,
+    enhancer?: StoreEnhancer<S, A, D>
+  ): Store<S, A, D>;
+
   declare export function applyMiddleware<S, A, D>(
     ...middlewares: Array<Middleware<S, A, D>>
   ): StoreEnhancer<S, A, D>;
@@ -91,9 +96,9 @@
     dispatch: D
   ): C;
 
-  declare export function combineReducers<O: {...}, A>(
-    reducers: O
-  ): CombinedReducer<$ObjMap<O, <S>(r: Reducer<S, any>) => S>, A>;
+  declare export function combineReducers<RootState: {...}, A>(
+    reducers: $ObjMap<RootState, <V>(V) => Reducer<V, A>>,
+  ): Reducer<RootState, A>;
 
   declare export var compose: $Compose;
 }
diff --git a/native/flow-typed/npm/redux_v4.x.x.js b/native/flow-typed/npm/redux_v4.x.x.js
--- a/native/flow-typed/npm/redux_v4.x.x.js
+++ b/native/flow-typed/npm/redux_v4.x.x.js
@@ -1,5 +1,5 @@
-// flow-typed signature: cf5a251230b87bfccb7000d63228c501
-// flow-typed version: 7735fcd9c6/redux_v4.x.x/flow_>=v0.134.x
+// flow-typed signature: f42950aebee3189b48dae0d4697c6776
+// flow-typed version: 0e28de5e8a/redux_v4.x.x/flow_>=v0.201.x
 
 declare module 'redux' {
   /*
@@ -14,7 +14,7 @@
 
   declare export type DispatchAPI<A> = (action: A) => A;
 
-  declare export type Dispatch<A: { +type: *, ... }> = DispatchAPI<A>;
+  declare export type Dispatch<A: { type: any, ... }> = DispatchAPI<A>;
 
   declare export type MiddlewareAPI<S, A, D = Dispatch<A>> = {
     dispatch: D,
@@ -31,12 +31,7 @@
     ...
   };
 
-  declare export type Reducer<S, A> = (state: S | void, action: A) => S;
-
-  declare export type CombinedReducer<S, A> = (
-    state: ($Shape<S> & {...}) | void,
-    action: A
-  ) => S;
+  declare export type Reducer<S, A> = (state: S, action: A) => S;
 
   declare export type Middleware<S, A, D = Dispatch<A>> = (
     api: MiddlewareAPI<S, A, D>
@@ -66,6 +61,16 @@
     enhancer?: StoreEnhancer<S, A, D>
   ): Store<S, A, D>;
 
+  declare export function legacy_createStore<S, A, D>(
+    reducer: Reducer<S, A>,
+    enhancer?: StoreEnhancer<S, A, D>
+  ): Store<S, A, D>;
+  declare export function legacy_createStore<S, A, D>(
+    reducer: Reducer<S, A>,
+    preloadedState?: S,
+    enhancer?: StoreEnhancer<S, A, D>
+  ): Store<S, A, D>;
+
   declare export function applyMiddleware<S, A, D>(
     ...middlewares: Array<Middleware<S, A, D>>
   ): StoreEnhancer<S, A, D>;
@@ -91,9 +96,9 @@
     dispatch: D
   ): C;
 
-  declare export function combineReducers<O: {...}, A>(
-    reducers: O
-  ): CombinedReducer<$ObjMap<O, <S>(r: Reducer<S, any>) => S>, A>;
+  declare export function combineReducers<RootState: {...}, A>(
+    reducers: $ObjMap<RootState, <V>(V) => Reducer<V, A>>,
+  ): Reducer<RootState, A>;
 
   declare export var compose: $Compose;
 }
diff --git a/web/flow-typed/npm/redux_v4.x.x.js b/web/flow-typed/npm/redux_v4.x.x.js
--- a/web/flow-typed/npm/redux_v4.x.x.js
+++ b/web/flow-typed/npm/redux_v4.x.x.js
@@ -1,5 +1,5 @@
-// flow-typed signature: cf5a251230b87bfccb7000d63228c501
-// flow-typed version: 7735fcd9c6/redux_v4.x.x/flow_>=v0.134.x
+// flow-typed signature: f42950aebee3189b48dae0d4697c6776
+// flow-typed version: 0e28de5e8a/redux_v4.x.x/flow_>=v0.201.x
 
 declare module 'redux' {
   /*
@@ -14,7 +14,7 @@
 
   declare export type DispatchAPI<A> = (action: A) => A;
 
-  declare export type Dispatch<A: { +type: *, ... }> = DispatchAPI<A>;
+  declare export type Dispatch<A: { type: any, ... }> = DispatchAPI<A>;
 
   declare export type MiddlewareAPI<S, A, D = Dispatch<A>> = {
     dispatch: D,
@@ -31,12 +31,7 @@
     ...
   };
 
-  declare export type Reducer<S, A> = (state: S | void, action: A) => S;
-
-  declare export type CombinedReducer<S, A> = (
-    state: ($Shape<S> & {...}) | void,
-    action: A
-  ) => S;
+  declare export type Reducer<S, A> = (state: S, action: A) => S;
 
   declare export type Middleware<S, A, D = Dispatch<A>> = (
     api: MiddlewareAPI<S, A, D>
@@ -66,6 +61,16 @@
     enhancer?: StoreEnhancer<S, A, D>
   ): Store<S, A, D>;
 
+  declare export function legacy_createStore<S, A, D>(
+    reducer: Reducer<S, A>,
+    enhancer?: StoreEnhancer<S, A, D>
+  ): Store<S, A, D>;
+  declare export function legacy_createStore<S, A, D>(
+    reducer: Reducer<S, A>,
+    preloadedState?: S,
+    enhancer?: StoreEnhancer<S, A, D>
+  ): Store<S, A, D>;
+
   declare export function applyMiddleware<S, A, D>(
     ...middlewares: Array<Middleware<S, A, D>>
   ): StoreEnhancer<S, A, D>;
@@ -91,9 +96,9 @@
     dispatch: D
   ): C;
 
-  declare export function combineReducers<O: {...}, A>(
-    reducers: O
-  ): CombinedReducer<$ObjMap<O, <S>(r: Reducer<S, any>) => S>, A>;
+  declare export function combineReducers<RootState: {...}, A>(
+    reducers: $ObjMap<RootState, <V>(V) => Reducer<V, A>>,
+  ): Reducer<RootState, A>;
 
   declare export var compose: $Compose;
 }