Index: test/std/localization/locale.categories/category.collate/locale.collate.byname/compare.pass.cpp
===================================================================
--- test/std/localization/locale.categories/category.collate/locale.collate.byname/compare.pass.cpp
+++ test/std/localization/locale.categories/category.collate/locale.collate.byname/compare.pass.cpp
@@ -7,6 +7,8 @@
 //
 //===----------------------------------------------------------------------===//
 
+// REQUIRES: locale.en_US.UTF-8
+
 // <locale>
 
 // template <class charT> class collate_byname
Index: test/std/localization/locale.categories/category.ctype/locale.ctype.byname/tolower_1.pass.cpp
===================================================================
--- test/std/localization/locale.categories/category.ctype/locale.ctype.byname/tolower_1.pass.cpp
+++ test/std/localization/locale.categories/category.ctype/locale.ctype.byname/tolower_1.pass.cpp
@@ -7,6 +7,8 @@
 //
 //===----------------------------------------------------------------------===//
 
+// REQUIRES: locale.en_US.UTF-8
+
 // <locale>
 
 // template <class charT> class ctype_byname;
Index: test/std/localization/locale.categories/category.ctype/locale.ctype.byname/tolower_many.pass.cpp
===================================================================
--- test/std/localization/locale.categories/category.ctype/locale.ctype.byname/tolower_many.pass.cpp
+++ test/std/localization/locale.categories/category.ctype/locale.ctype.byname/tolower_many.pass.cpp
@@ -7,6 +7,8 @@
 //
 //===----------------------------------------------------------------------===//
 
+// REQUIRES: locale.en_US.UTF-8
+
 // <locale>
 
 // template <class charT> class ctype_byname;
Index: test/std/localization/locale.categories/category.ctype/locale.ctype.byname/toupper_1.pass.cpp
===================================================================
--- test/std/localization/locale.categories/category.ctype/locale.ctype.byname/toupper_1.pass.cpp
+++ test/std/localization/locale.categories/category.ctype/locale.ctype.byname/toupper_1.pass.cpp
@@ -7,6 +7,8 @@
 //
 //===----------------------------------------------------------------------===//
 
+// REQUIRES: locale.en_US.UTF-8
+
 // <locale>
 
 // template <class charT> class ctype_byname;
Index: test/std/localization/locale.categories/category.ctype/locale.ctype.byname/toupper_many.pass.cpp
===================================================================
--- test/std/localization/locale.categories/category.ctype/locale.ctype.byname/toupper_many.pass.cpp
+++ test/std/localization/locale.categories/category.ctype/locale.ctype.byname/toupper_many.pass.cpp
@@ -7,6 +7,8 @@
 //
 //===----------------------------------------------------------------------===//
 
+// REQUIRES: locale.en_US.UTF-8
+
 // <locale>
 
 // template <class charT> class ctype_byname;
Index: test/std/localization/locale.categories/category.ctype/locale.ctype.byname/widen_1.pass.cpp
===================================================================
--- test/std/localization/locale.categories/category.ctype/locale.ctype.byname/widen_1.pass.cpp
+++ test/std/localization/locale.categories/category.ctype/locale.ctype.byname/widen_1.pass.cpp
@@ -7,6 +7,8 @@
 //
 //===----------------------------------------------------------------------===//
 
+// REQUIRES: locale.en_US.UTF-8
+
 // <locale>
 
 // template <class charT> class ctype_byname;
Index: test/std/localization/locale.categories/category.ctype/locale.ctype.byname/widen_many.pass.cpp
===================================================================
--- test/std/localization/locale.categories/category.ctype/locale.ctype.byname/widen_many.pass.cpp
+++ test/std/localization/locale.categories/category.ctype/locale.ctype.byname/widen_many.pass.cpp
@@ -7,6 +7,8 @@
 //
 //===----------------------------------------------------------------------===//
 
+// REQUIRES: locale.en_US.UTF-8
+
 // <locale>
 
 // template <class charT> class ctype_byname;