diff --git a/include/__config b/include/__config
index 1fedc04..a70f8f0 100644
--- a/include/__config
+++ b/include/__config
@@ -817,7 +817,9 @@
 #   else
 #       error Supported values for _LIBCPP_DEBUG are 0 and 1
 #   endif
+# if !defined(_LIBCPP_BUILDING_LIBRARY)
 #   define _LIBCPP_EXTERN_TEMPLATE(...)
+# endif
 #endif
 
 #ifndef _LIBCPP_EXTERN_TEMPLATE