diff --git a/packages/react-navigation/typescript/react-navigation.d.ts b/packages/react-navigation/typescript/react-navigation.d.ts
index ee78edb9..08a53431 100644
--- a/packages/react-navigation/typescript/react-navigation.d.ts
+++ b/packages/react-navigation/typescript/react-navigation.d.ts
@@ -269,7 +269,7 @@ declare module 'react-navigation' {
     key: string;
 
     // The new params to merge into the existing route params
-    params?: NavigationParams;
+    params: NavigationParams;
   }
 
   export interface NavigationSetParamsAction