1 files changed, 3 insertions, 1 deletions
diff --git a/libcxx/test/input.output/stream.buffers/streambuf/streambuf.cons/copy.pass.cpp b/libcxx/test/input.output/stream.buffers/streambuf/streambuf.cons/copy.pass.cpp
index ffad159f8f8..8af132e5be6 100644
--- a/libcxx/test/input.output/stream.buffers/streambuf/streambuf.cons/copy.pass.cpp
+++ b/libcxx/test/input.output/stream.buffers/streambuf/streambuf.cons/copy.pass.cpp
@@ -17,6 +17,8 @@
 #include <streambuf>
 #include <cassert>
 
+#include "../../../../platform_support.h" // locale name macros
+
 template <class CharT>
 struct test
     : public std::basic_streambuf<CharT>
@@ -70,7 +72,7 @@ int main()
         t.setp(&p1, &p3);
         test<wchar_t> t2 = t;
     }
-    std::locale::global(std::locale("en_US.UTF-8"));
+    std::locale::global(std::locale(LOCALE_en_US_UTF_8));
     {
         test<char> t;
         test<char> t2 = t;