diff --git a/strings/base_extern.h b/strings/base_extern.h
index a17908ac4..319343095 100644
--- a/strings/base_extern.h
+++ b/strings/base_extern.h
@@ -25,6 +25,10 @@ WINRT_EXPORT __declspec(selectany) std::int32_t(__stdcall* winrt_activation_hand
 #endif
 #endif
 
+// Windows.Foundation.ixx needs to access them.
+#ifdef WINRT_IMPL_BUILD_MODULE
+export
+#endif
 extern "C"
 {
     std::int32_t __stdcall WINRT_IMPL_RoGetActivationFactory(void* classId, winrt::guid const& iid, void** factory) noexcept WINRT_IMPL_LINK(RoGetActivationFactory, 12);