diff --git a/libcxx/include/__cstddef/max_align_t.h b/libcxx/include/__cstddef/max_align_t.h
index 7c09c7e7f3017..d97c779b1cb6a 100644
--- a/libcxx/include/__cstddef/max_align_t.h
+++ b/libcxx/include/__cstddef/max_align_t.h
@@ -19,7 +19,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 #if !defined(_LIBCPP_CXX03_LANG)
-using ::max_align_t _LIBCPP_USING_IF_EXISTS;
+using ::max_align_t;
 #endif
 
 _LIBCPP_END_NAMESPACE_STD
diff --git a/libcxx/include/__cstddef/ptrdiff_t.h b/libcxx/include/__cstddef/ptrdiff_t.h
index f8b5cdaaff01c..28068b492c3a8 100644
--- a/libcxx/include/__cstddef/ptrdiff_t.h
+++ b/libcxx/include/__cstddef/ptrdiff_t.h
@@ -18,7 +18,7 @@
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
-using ::ptrdiff_t _LIBCPP_USING_IF_EXISTS;
+using ::ptrdiff_t;
 
 _LIBCPP_END_NAMESPACE_STD
 
diff --git a/libcxx/include/__cstddef/size_t.h b/libcxx/include/__cstddef/size_t.h
index 91abbf0131895..24875a2c81359 100644
--- a/libcxx/include/__cstddef/size_t.h
+++ b/libcxx/include/__cstddef/size_t.h
@@ -18,7 +18,7 @@
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
-using ::size_t _LIBCPP_USING_IF_EXISTS;
+using ::size_t;
 
 _LIBCPP_END_NAMESPACE_STD