diff --git a/include/ctype.h b/include/ctype.h
index a6f44df..eef574b 100644
--- a/include/ctype.h
+++ b/include/ctype.h
@@ -27,6 +27,7 @@ static __inline int __isspace(int _c)
 	return _c == ' ' || (unsigned)_c-'\t' < 5;
 }
 
+#ifndef __cplusplus
 #define isalpha(a) ((((unsigned)(a)|32)-'a') < 26)
 #define isdigit(a) (((unsigned)(a)-'0') < 10)
 #define islower(a) (((unsigned)(a)-'a') < 26)
@@ -34,6 +35,7 @@ static __inline int __isspace(int _c)
 #define isprint(a) (((unsigned)(a)-0x20) < 0x5f)
 #define isgraph(a) (((unsigned)(a)-0x21) < 0x5e)
 #define isspace(a) __isspace(a)
+#endif
 
 
 #if defined(_POSIX_SOURCE) || defined(_POSIX_C_SOURCE) \
diff --git a/include/wchar.h b/include/wchar.h
index 9fd967c..8cfb584 100644
--- a/include/wchar.h
+++ b/include/wchar.h
@@ -176,9 +176,12 @@ int       iswctype(wint_t, wctype_t);
 wint_t    towlower(wint_t);
 wint_t    towupper(wint_t);
 wctype_t  wctype(const char *);
+
+#ifndef __cplusplus
 #undef iswdigit
 #define iswdigit(a) ((unsigned)(a)-'0' < 10)
 #endif
+#endif
 
 #ifdef __cplusplus
 }
diff --git a/include/wctype.h b/include/wctype.h
index 3ac24f1..3da1219 100644
--- a/include/wctype.h
+++ b/include/wctype.h
@@ -43,8 +43,10 @@ wint_t    towupper(wint_t);
 wctrans_t wctrans(const char *);
 wctype_t  wctype(const char *);
 
+#ifndef __cplusplus
 #undef iswdigit
 #define iswdigit(a) (((unsigned)(a)-L'0') < 10)
+#endif
 
 #if defined(_POSIX_SOURCE) || defined(_POSIX_C_SOURCE) \
  || defined(_XOPEN_SOURCE) || defined(_GNU_SOURCE) || defined(_BSD_SOURCE)