diff --git a/include/ctype.h b/include/ctype.h
index 554ece9553..2282bd09db 100644
--- a/include/ctype.h
+++ b/include/ctype.h
@@ -35,7 +35,7 @@
 #include <nuttx/compiler.h>
 #include <langinfo.h>
 
-#ifndef _MSC_VER
+#ifdef CONFIG_LIBCXXTOOLCHAIN
 
 /* GNU libstdc++ is expecting ctype.h to define a few macros for
  * locale related functions like C++ streams.
diff --git a/libs/libc/ctype/lib_ctype.c b/libs/libc/ctype/lib_ctype.c
index b97076cc97..d369a33f31 100644
--- a/libs/libc/ctype/lib_ctype.c
+++ b/libs/libc/ctype/lib_ctype.c
@@ -32,7 +32,7 @@
  * Macro Definitions
  ****************************************************************************/
 
-#if defined(_MSC_VER)
+#ifndef CONFIG_LIBCXXTOOLCHAIN
 
 /* MSVC seems to conflict with theses macro if defined in the public area.
  * As such, they are defined in the private section to let NuttX build
@@ -47,7 +47,7 @@
 #define _X  0100
 #define _B  0200
 
-#endif
+#else
 
 /****************************************************************************
  * Private Types
@@ -98,3 +98,6 @@ const char _ctype_[] =
 /****************************************************************************
  * Private Functions
  ****************************************************************************/
+
+#endif
+