diff --git a/types/react-navigation/index.d.ts b/types/react-navigation/index.d.ts
index 48c3c59e85..40b83778e0 100644
--- a/types/react-navigation/index.d.ts
+++ b/types/react-navigation/index.d.ts
@@ -477,7 +477,7 @@ export interface LayoutEvent {
 }
 
 interface NavigationContainerProps {
-  navigation: NavigationProp<any, NavigationAction>
+  navigation?: NavigationProp<any, NavigationAction>
   onNavigationStateChange?: (
     preNavigationState: NavigationState,
     nextNavigationState: NavigationState,
@@ -571,7 +571,7 @@ export interface StackNavigatorScreenOptions {
   title?: string;
   headerVisible?: boolean;
   headerTitle?: string|React.ReactElement<any>;
-  headerBackTitle?: string|null;
+  headerBackTitle?: string;
   headerTruncatedBackTitle?: string;
   headerRight?: React.ReactElement<any>;
   headerLeft?: React.ReactElement<any>;