diff --git a/libcxx/include/__config b/libcxx/include/__config
--- a/libcxx/include/__config
+++ b/libcxx/include/__config
@@ -294,16 +294,6 @@
 #    define _LIBCPP_HAS_BITSCAN64
 #  endif
 #  define _LIBCPP_HAS_OPEN_WITH_WCHAR
-
-// Some CRT APIs are unavailable to store apps
-#  if defined(WINAPI_FAMILY)
-#    include <winapifamily.h>
-#    if !WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_DESKTOP) &&                  \
-        (!defined(WINAPI_PARTITION_SYSTEM) ||                                  \
-         !WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_SYSTEM))
-#      define _LIBCPP_WINDOWS_STORE_APP
-#    endif
-#  endif
 #endif // defined(_WIN32)
 
 #ifdef __sun__
diff --git a/libcxx/include/cstdlib b/libcxx/include/cstdlib
--- a/libcxx/include/cstdlib
+++ b/libcxx/include/cstdlib
@@ -115,10 +115,8 @@
 using ::atexit _LIBCPP_USING_IF_EXISTS;
 using ::exit _LIBCPP_USING_IF_EXISTS;
 using ::_Exit _LIBCPP_USING_IF_EXISTS;
-#ifndef _LIBCPP_WINDOWS_STORE_APP
 using ::getenv _LIBCPP_USING_IF_EXISTS;
 using ::system _LIBCPP_USING_IF_EXISTS;
-#endif
 using ::bsearch _LIBCPP_USING_IF_EXISTS;
 using ::qsort _LIBCPP_USING_IF_EXISTS;
 using ::abs _LIBCPP_USING_IF_EXISTS;