diff --git a/types/react-router/index.d.ts b/types/react-router/index.d.ts
index 3e9471e0ae..5c259f4a05 100644
--- a/types/react-router/index.d.ts
+++ b/types/react-router/index.d.ts
@@ -20,6 +20,7 @@
 //                 Wesley Tsai <https://github.com/wezleytsai>
 //                 Sebastian Silbermann <https://github.com/eps1lon>
 //                 Nicholas Hehr <https://github.com/HipsterBrown>
+//                 Pawel Fajfer <https://github.com/pawfa>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
 // TypeScript Version: 2.8
 
@@ -161,7 +162,7 @@ export function useHistory<HistoryLocationState = H.LocationState>(): H.History<
 
 export function useLocation<S = H.LocationState>(): H.Location<S>;
 
-export function useParams<Params extends { [K in keyof Params]?: string } = {}>(): { [p in keyof Params]: string };
+export function useParams<Params extends { [K in keyof Params]?: string } = {}>(): { [p in keyof Params]: keyof Params[p] extends undefined ? string | undefined : string  };
 
 export function useRouteMatch<Params extends { [K in keyof Params]?: string } = {}>(): match<Params>;
 export function useRouteMatch<Params extends { [K in keyof Params]?: string } = {}>(
diff --git a/types/react-router/test/hooks.tsx b/types/react-router/test/hooks.tsx
index 031d854826..269a3e04e1 100644
--- a/types/react-router/test/hooks.tsx
+++ b/types/react-router/test/hooks.tsx
@@ -5,6 +5,11 @@ interface Params {
     id: string;
 }
 
+interface OptionalParams {
+    id?: string;
+    s: string | undefined;
+}
+
 interface LocationState {
     s: string;
 }
@@ -14,6 +19,8 @@ const HooksTest: React.FC = () => {
     const location = useLocation<LocationState>();
     const { id } = useParams();
     const params = useParams<Params>();
+    // $ExpectType { id?: string | undefined; s: string | undefined; }
+    const optionalParams = useParams<OptionalParams>();
     // $ExpectType match<Params> | null
     const match1 = useRouteMatch<Params>('/:id');
     // $ExpectType match<Params> | null
@@ -27,6 +34,8 @@ const HooksTest: React.FC = () => {
     location.state.s;
     id && id.replace;
     params.id.replace;
+    optionalParams.id && optionalParams.id.replace;
+    optionalParams.s && optionalParams.s.replace;
     match1 && match1.params.id.replace;
     match2 && match2.params.id.replace;
     match3 && match3.params.id.replace;