diff --git a/libcxx/test/std/localization/locale.categories/category.ctype/locale.codecvt/locale.codecvt.members/char16_t_in.pass.cpp b/libcxx/test/std/localization/locale.categories/category.ctype/locale.codecvt/locale.codecvt.members/char16_t_in.pass.cpp
--- a/libcxx/test/std/localization/locale.categories/category.ctype/locale.codecvt/locale.codecvt.members/char16_t_in.pass.cpp
+++ b/libcxx/test/std/localization/locale.categories/category.ctype/locale.codecvt/locale.codecvt.members/char16_t_in.pass.cpp
@@ -17,6 +17,8 @@
 // This test runs in C++20, but we have deprecated codecvt<char(16|32), char, mbstate_t> in C++20.
 // ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS
 
+// UNSUPPORTED: target={{.+}}-zos{{.*}}
+
 #include <locale>
 #include <string>
 #include <vector>
diff --git a/libcxx/test/std/localization/locale.categories/category.ctype/locale.codecvt/locale.codecvt.members/char16_t_length.pass.cpp b/libcxx/test/std/localization/locale.categories/category.ctype/locale.codecvt/locale.codecvt.members/char16_t_length.pass.cpp
--- a/libcxx/test/std/localization/locale.categories/category.ctype/locale.codecvt/locale.codecvt.members/char16_t_length.pass.cpp
+++ b/libcxx/test/std/localization/locale.categories/category.ctype/locale.codecvt/locale.codecvt.members/char16_t_length.pass.cpp
@@ -15,6 +15,8 @@
 // This test runs in C++20, but we have deprecated codecvt<char(16|32), char, mbstate_t> in C++20.
 // ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS
 
+// UNSUPPORTED: target={{.+}}-zos{{.*}}
+
 #include <locale>
 #include <cassert>
 
diff --git a/libcxx/test/std/localization/locale.categories/category.ctype/locale.codecvt/locale.codecvt.members/char32_t_in.pass.cpp b/libcxx/test/std/localization/locale.categories/category.ctype/locale.codecvt/locale.codecvt.members/char32_t_in.pass.cpp
--- a/libcxx/test/std/localization/locale.categories/category.ctype/locale.codecvt/locale.codecvt.members/char32_t_in.pass.cpp
+++ b/libcxx/test/std/localization/locale.categories/category.ctype/locale.codecvt/locale.codecvt.members/char32_t_in.pass.cpp
@@ -17,6 +17,8 @@
 // This test runs in C++20, but we have deprecated codecvt<char(16|32), char, mbstate_t> in C++20.
 // ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS
 
+// UNSUPPORTED: target={{.+}}-zos{{.*}}
+
 #include <locale>
 #include <string>
 #include <vector>
diff --git a/libcxx/test/std/localization/locale.categories/category.ctype/locale.codecvt/locale.codecvt.members/char32_t_length.pass.cpp b/libcxx/test/std/localization/locale.categories/category.ctype/locale.codecvt/locale.codecvt.members/char32_t_length.pass.cpp
--- a/libcxx/test/std/localization/locale.categories/category.ctype/locale.codecvt/locale.codecvt.members/char32_t_length.pass.cpp
+++ b/libcxx/test/std/localization/locale.categories/category.ctype/locale.codecvt/locale.codecvt.members/char32_t_length.pass.cpp
@@ -15,6 +15,8 @@
 // This test runs in C++20, but we have deprecated codecvt<char(16|32), char, mbstate_t> in C++20.
 // ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS
 
+// UNSUPPORTED: target={{.+}}-zos{{.*}}
+
 #include <locale>
 #include <cassert>