diff --git a/strings/base_natvis.h b/strings/base_natvis.h
index 065550759..8ff4bd145 100644
--- a/strings/base_natvis.h
+++ b/strings/base_natvis.h
@@ -1,5 +1,5 @@
 
-#ifdef _DEBUG
+#if defined(_DEBUG) && !defined(WINRT_NATVIS)
 #define WINRT_NATVIS
 #endif