diff --git a/src/cxa_guard_impl.h b/src/cxa_guard_impl.h
index ea82d20..412099e 100644
--- a/src/cxa_guard_impl.h
+++ b/src/cxa_guard_impl.h
@@ -257,6 +257,9 @@
 private:
   std::__libcpp_condvar_t cond = _LIBCPP_CONDVAR_INITIALIZER;
 };
+#else
+struct LibcppMutex {};
+struct LibcppCondVar {};
 #endif // !defined(_LIBCXXABI_HAS_NO_THREADS)