Index: libcxx/test/std/language.support/support.dynamic/align_val_t.pass.cpp
===================================================================
--- libcxx/test/std/language.support/support.dynamic/align_val_t.pass.cpp
+++ libcxx/test/std/language.support/support.dynamic/align_val_t.pass.cpp
@@ -10,6 +10,10 @@
 
 // UNSUPPORTED: c++03, c++11, c++14
 
+// Libcxx when built for z/OS doesn't contain the aligned allocation functions,
+// nor does the dynamic library shipped with z/OS.
+// UNSUPPORTED: target={{.+}}-zos{{.*}}
+
 #include <new>
 
 #include "test_macros.h"
Index: libcxx/test/std/language.support/support.dynamic/new.delete/new.delete.array/new_size_align.verify.cpp
===================================================================
--- libcxx/test/std/language.support/support.dynamic/new.delete/new.delete.array/new_size_align.verify.cpp
+++ libcxx/test/std/language.support/support.dynamic/new.delete/new.delete.array/new_size_align.verify.cpp
@@ -13,6 +13,10 @@
 
 // UNSUPPORTED: c++03, c++11, c++14, c++17
 
+// Libcxx when built for z/OS doesn't contain the aligned allocation functions,
+// nor does the dynamic library shipped with z/OS.
+// UNSUPPORTED: target={{.+}}-zos{{.*}}
+
 // REQUIRES: -faligned-allocation
 // ADDITIONAL_COMPILE_FLAGS: -faligned-allocation
 
Index: libcxx/test/std/language.support/support.dynamic/new.delete/new.delete.array/new_size_align_nothrow.verify.cpp
===================================================================
--- libcxx/test/std/language.support/support.dynamic/new.delete/new.delete.array/new_size_align_nothrow.verify.cpp
+++ libcxx/test/std/language.support/support.dynamic/new.delete/new.delete.array/new_size_align_nothrow.verify.cpp
@@ -13,6 +13,10 @@
 
 // UNSUPPORTED: c++03, c++11, c++14, c++17
 
+// Libcxx when built for z/OS doesn't contain the aligned allocation functions,
+// nor does the dynamic library shipped with z/OS.
+// UNSUPPORTED: target={{.+}}-zos{{.*}}
+
 // REQUIRES: -faligned-allocation
 // ADDITIONAL_COMPILE_FLAGS: -faligned-allocation
 
Index: libcxx/test/std/language.support/support.dynamic/new.delete/new.delete.single/new_size_align.verify.cpp
===================================================================
--- libcxx/test/std/language.support/support.dynamic/new.delete/new.delete.single/new_size_align.verify.cpp
+++ libcxx/test/std/language.support/support.dynamic/new.delete/new.delete.single/new_size_align.verify.cpp
@@ -13,6 +13,10 @@
 
 // UNSUPPORTED: c++03, c++11, c++14, c++17
 
+// Libcxx when built for z/OS doesn't contain the aligned allocation functions,
+// nor does the dynamic library shipped with z/OS.
+// UNSUPPORTED: target={{.+}}-zos{{.*}}
+
 // REQUIRES: -faligned-allocation
 // ADDITIONAL_COMPILE_FLAGS: -faligned-allocation
 
Index: libcxx/test/std/language.support/support.dynamic/new.delete/new.delete.single/new_size_align_nothrow.verify.cpp
===================================================================
--- libcxx/test/std/language.support/support.dynamic/new.delete/new.delete.single/new_size_align_nothrow.verify.cpp
+++ libcxx/test/std/language.support/support.dynamic/new.delete/new.delete.single/new_size_align_nothrow.verify.cpp
@@ -13,6 +13,10 @@
 
 // UNSUPPORTED: c++03, c++11, c++14, c++17
 
+// Libcxx when built for z/OS doesn't contain the aligned allocation functions,
+// nor does the dynamic library shipped with z/OS.
+// UNSUPPORTED: target={{.+}}-zos{{.*}}
+
 // REQUIRES: -faligned-allocation
 // ADDITIONAL_COMPILE_FLAGS: -faligned-allocation