diff --git a/packages/metro/src/ModuleGraph/types.flow.js b/packages/metro/src/ModuleGraph/types.flow.js
index 74d2d32c07..177126a067 100644
--- a/packages/metro/src/ModuleGraph/types.flow.js
+++ b/packages/metro/src/ModuleGraph/types.flow.js
@@ -315,6 +315,8 @@ export type ResolvedLibrary = {
   +files: $ReadOnlyArray<$DeepReadOnly<ResolvedCodeFile>>,
   /* cannot be a Map because it's JSONified later on */
   +assets: AssetContentsByPath,
+
+  +isUnsupportedPlatform?: boolean,
 };
 
 type DeepReadOnlyFn = (<T>(Array<T>) => $ReadOnlyArray<$DeepReadOnly<T>>) &