diff --git a/ddr/include/ddr/std/string.hpp b/ddr/include/ddr/std/string.hpp
index 486396c3876..e57b4cae799 100644
--- a/ddr/include/ddr/std/string.hpp
+++ b/ddr/include/ddr/std/string.hpp
@@ -27,14 +27,8 @@
 #if defined(J9ZOS390)
 
 #include <ctype.h>
-#undef toupper
-#undef tolower
-
 #include <string>
 
-#define toupper(c)     (islower(c) ? (c & _XUPPER_ASCII) : c)
-#define tolower(c)     (isupper(c) ? (c | _XLOWER_ASCII) : c)
-
 #else /* defined(J9ZOS390) */
 #include <string>
 #endif /* defined(J9ZOS390) */
diff --git a/ddr/include/ddr/std/unordered_map.hpp b/ddr/include/ddr/std/unordered_map.hpp
index 7e72c2f9b83..0aebebad25e 100644
--- a/ddr/include/ddr/std/unordered_map.hpp
+++ b/ddr/include/ddr/std/unordered_map.hpp
@@ -26,8 +26,6 @@
 
 #if defined(J9ZOS390)
 #include <ctype.h>
-#undef toupper
-#undef tolower
 #endif /* defined(J9ZOS390) */
 
 #include <unordered_map>
@@ -38,9 +36,4 @@ using std::unordered_map;
 using std::tr1::unordered_map;
 #endif /* defined(OMR_HAVE_CXX11) */
 
-#if defined(J9ZOS390)
-#define toupper(c)     (islower(c) ? (c & _XUPPER_ASCII) : c)
-#define tolower(c)     (isupper(c) ? (c | _XLOWER_ASCII) : c)
-#endif /* defined(J9ZOS390) */
-
 #endif /* DDR_UNORDERED_MAP */