diff --git a/include/ctype.h b/include/ctype.h
index a6f44df..7f8d98d 100644
--- a/include/ctype.h
+++ b/include/ctype.h
@@ -8,16 +8,9 @@ extern "C" {
 #include <features.h>
 
 int   isalnum(int);
-int   isalpha(int);
 int   isblank(int);
 int   iscntrl(int);
-int   isdigit(int);
-int   isgraph(int);
-int   islower(int);
-int   isprint(int);
 int   ispunct(int);
-int   isspace(int);
-int   isupper(int);
 int   isxdigit(int);
 int   tolower(int);
 int   toupper(int);
@@ -27,14 +20,40 @@ static __inline int __isspace(int _c)
 	return _c == ' ' || (unsigned)_c-'\t' < 5;
 }
 
-#define isalpha(a) ((((unsigned)(a)|32)-'a') < 26)
-#define isdigit(a) (((unsigned)(a)-'0') < 10)
-#define islower(a) (((unsigned)(a)-'a') < 26)
-#define isupper(a) (((unsigned)(a)-'A') < 26)
-#define isprint(a) (((unsigned)(a)-0x20) < 0x5f)
-#define isgraph(a) (((unsigned)(a)-0x21) < 0x5e)
-#define isspace(a) __isspace(a)
+__inline int isalpha(int _c)
+{
+	return (((unsigned)_c | 32) - 'a') < 26;
+}
+
+__inline int isdigit(int _c)
+{
+	return ((unsigned)_c - '0') < 10;
+}
 
+__inline int islower(int _c)
+{
+	return ((unsigned)_c - 'a') < 26;
+}
+
+__inline int isupper(int _c)
+{
+	return ((unsigned)_c - 'A') < 26;
+}
+
+__inline int isprint(int _c)
+{
+	return ((unsigned)_c - 0x20) < 0x5f;
+}
+
+__inline int isgraph(int _c)
+{
+	return ((unsigned)_c - 0x21) < 0x5e;
+}
+
+__inline int isspace(int _c)
+{
+	return __isspace(_c);
+}
 
 #if defined(_POSIX_SOURCE) || defined(_POSIX_C_SOURCE) \
  || defined(_XOPEN_SOURCE) || defined(_GNU_SOURCE) \
diff --git a/include/wchar.h b/include/wchar.h
index 9fd967c..3033df8 100644
--- a/include/wchar.h
+++ b/include/wchar.h
@@ -138,8 +138,6 @@ wint_t ungetwc (wint_t, FILE *);
 struct tm;
 size_t wcsftime (wchar_t *__restrict, size_t, const wchar_t *__restrict, const struct tm *__restrict);
 
-#undef iswdigit
-
 #if defined(_POSIX_SOURCE) || defined(_POSIX_C_SOURCE) \
  || defined(_XOPEN_SOURCE) || defined(_GNU_SOURCE)  || defined(_BSD_SOURCE)
 FILE *open_wmemstream(wchar_t **, size_t *);
@@ -164,7 +162,6 @@ int       iswalnum(wint_t);
 int       iswalpha(wint_t);
 int       iswblank(wint_t);
 int       iswcntrl(wint_t);
-int       iswdigit(wint_t);
 int       iswgraph(wint_t);
 int       iswlower(wint_t);
 int       iswprint(wint_t);
@@ -176,8 +173,15 @@ int       iswctype(wint_t, wctype_t);
 wint_t    towlower(wint_t);
 wint_t    towupper(wint_t);
 wctype_t  wctype(const char *);
-#undef iswdigit
-#define iswdigit(a) ((unsigned)(a)-'0' < 10)
+
+#ifndef __iswdigit_defined
+#define __iswdigit_defined
+__inline int iswdigit(wint_t _c)
+{
+	return ((unsigned)_c - L'0') < 10;
+}
+#endif
+
 #endif
 
 #ifdef __cplusplus
diff --git a/include/wctype.h b/include/wctype.h
index 3ac24f1..3747c87 100644
--- a/include/wctype.h
+++ b/include/wctype.h
@@ -22,13 +22,10 @@ typedef const int * wctrans_t;
 #undef WEOF
 #define WEOF 0xffffffffU
 
-#undef iswdigit
-
 int       iswalnum(wint_t);
 int       iswalpha(wint_t);
 int       iswblank(wint_t);
 int       iswcntrl(wint_t);
-int       iswdigit(wint_t);
 int       iswgraph(wint_t);
 int       iswlower(wint_t);
 int       iswprint(wint_t);
@@ -43,8 +40,13 @@ wint_t    towupper(wint_t);
 wctrans_t wctrans(const char *);
 wctype_t  wctype(const char *);
 
-#undef iswdigit
-#define iswdigit(a) (((unsigned)(a)-L'0') < 10)
+#ifndef __iswdigit_defined
+#define __iswdigit_defined
+__inline int iswdigit(wint_t _c)
+{
+	return ((unsigned)_c - L'0') < 10;
+}
+#endif
 
 #if defined(_POSIX_SOURCE) || defined(_POSIX_C_SOURCE) \
  || defined(_XOPEN_SOURCE) || defined(_GNU_SOURCE) || defined(_BSD_SOURCE)
diff --git a/src/ctype/isalpha.c b/src/ctype/isalpha.c
index f155d3a..b5403d6 100644
--- a/src/ctype/isalpha.c
+++ b/src/ctype/isalpha.c
@@ -1,11 +1,7 @@
 #include <ctype.h>
 #include "libc.h"
-#undef isalpha
 
-int isalpha(int c)
-{
-	return ((unsigned)c|32)-'a' < 26;
-}
+extern inline int isalpha(int);
 
 int __isalpha_l(int c, locale_t l)
 {
diff --git a/src/ctype/isdigit.c b/src/ctype/isdigit.c
index 4d8a103..b4e58d2 100644
--- a/src/ctype/isdigit.c
+++ b/src/ctype/isdigit.c
@@ -1,11 +1,7 @@
 #include <ctype.h>
 #include "libc.h"
-#undef isdigit
 
-int isdigit(int c)
-{
-	return (unsigned)c-'0' < 10;
-}
+extern inline int isdigit(int);
 
 int __isdigit_l(int c, locale_t l)
 {
diff --git a/src/ctype/isgraph.c b/src/ctype/isgraph.c
index a0aae08..b831164 100644
--- a/src/ctype/isgraph.c
+++ b/src/ctype/isgraph.c
@@ -1,11 +1,7 @@
 #include <ctype.h>
 #include "libc.h"
-#undef isgraph
 
-int isgraph(int c)
-{
-	return (unsigned)c-0x21 < 0x5e;
-}
+extern inline int isgraph(int);
 
 int __isgraph_l(int c, locale_t l)
 {
diff --git a/src/ctype/islower.c b/src/ctype/islower.c
index 0264021..3e3dde1 100644
--- a/src/ctype/islower.c
+++ b/src/ctype/islower.c
@@ -1,11 +1,7 @@
 #include <ctype.h>
 #include "libc.h"
-#undef islower
 
-int islower(int c)
-{
-	return (unsigned)c-'a' < 26;
-}
+extern inline int islower(int);
 
 int __islower_l(int c, locale_t l)
 {
diff --git a/src/ctype/isprint.c b/src/ctype/isprint.c
index 067275f..25dd9fc 100644
--- a/src/ctype/isprint.c
+++ b/src/ctype/isprint.c
@@ -1,11 +1,7 @@
 #include <ctype.h>
 #include "libc.h"
-#undef isprint
 
-int isprint(int c)
-{
-	return (unsigned)c-0x20 < 0x5f;
-}
+extern inline int isprint(int);
 
 int __isprint_l(int c, locale_t l)
 {
diff --git a/src/ctype/isspace.c b/src/ctype/isspace.c
index 231e907..86614a3 100644
--- a/src/ctype/isspace.c
+++ b/src/ctype/isspace.c
@@ -1,11 +1,7 @@
 #include <ctype.h>
 #include "libc.h"
-#undef isspace
 
-int isspace(int c)
-{
-	return c == ' ' || (unsigned)c-'\t' < 5;
-}
+extern inline int isspace(int);
 
 int __isspace_l(int c, locale_t l)
 {
diff --git a/src/ctype/isupper.c b/src/ctype/isupper.c
index 68c36f4..ef808e4 100644
--- a/src/ctype/isupper.c
+++ b/src/ctype/isupper.c
@@ -1,11 +1,7 @@
 #include <ctype.h>
 #include "libc.h"
-#undef isupper
 
-int isupper(int c)
-{
-	return (unsigned)c-'A' < 26;
-}
+extern inline int isupper(int);
 
 int __isupper_l(int c, locale_t l)
 {
diff --git a/src/ctype/iswdigit.c b/src/ctype/iswdigit.c
index ed9a88e..550d6e1 100644
--- a/src/ctype/iswdigit.c
+++ b/src/ctype/iswdigit.c
@@ -1,12 +1,7 @@
 #include <wctype.h>
 #include "libc.h"
 
-#undef iswdigit
-
-int iswdigit(wint_t wc)
-{
-	return (unsigned)wc-'0' < 10;
-}
+extern inline int iswdigit(wint_t);
 
 int __iswdigit_l(wint_t c, locale_t l)
 {