diff --git a/packages/core/src/types.tsx b/packages/core/src/types.tsx
index 5ea9aed2..7ac03bf2 100644
--- a/packages/core/src/types.tsx
+++ b/packages/core/src/types.tsx
@@ -632,10 +632,9 @@ export type PathConfig<ParamList extends {}> = {
 };
 
 export type PathConfigMap<ParamList extends {}> = {
-  [RouteName in keyof ParamList]?: ParamList[RouteName] extends NavigatorScreenParams<
-    infer T,
-    any
-  >
+  [RouteName in keyof ParamList]?: NonNullable<
+    ParamList[RouteName]
+  > extends NavigatorScreenParams<infer T, any>
     ? string | PathConfig<T>
     : string | Omit<PathConfig<{}>, 'screens' | 'initialRouteName'>;
 };