--- /dev/null
+// RUN: %clang_cc1 -fmodules -fobjc-arc -x objective-c-module-map %s -fmodule-name=Foo -verify
+
+module Foo {}
+
+#pragma clang module contents
+#pragma clang module begin Foo
+
+// expected-no-diagnostics
+
+#pragma clang module build Foundation
+module Foundation {}
+#pragma clang module contents
+#pragma clang module begin Foundation
+@interface NSIndexSet
+@end
+#pragma clang module end
+#pragma clang module endbuild
+
+#pragma clang module import Foundation
+
+@interface NSIndexSet (Testing)
+- (int)foo;
+@end
+
+static inline int test(NSIndexSet *obj) {
+ return [obj foo];
+}
+
+#pragma clang module end