diff --git a/include/ctype.h b/include/ctype.h
new file mode 100644
index 0000000..b5d1dc9
--- /dev/null
+++ b/include/ctype.h
@@ -0,0 +1,42 @@
+#ifndef __TL_CTYPE_H
+#define	__TL_CTYPE_H
+
+#ifdef __cplusplus
+extern "C"
+{
+#endif
+
+extern char g_ctype[];
+
+#define CT_UP	0x01	/* upper case */
+#define CT_LOW	0x02	/* lower case */
+#define CT_DIG	0x04	/* digit */
+#define CT_CTL	0x08	/* control */
+#define CT_PUN	0x10	/* punctuation */
+#define CT_WHT	0x20	/* white space (space/cr/lf/tab) */
+#define CT_HEX	0x40	/* hex digit */
+#define CT_SP	0x80	/* hard space (0x20) */
+
+/* without the cast to unsigned, DJGPP complains (using -Wall) */
+#define isalnum(c)	((g_ctype + 1)[(unsigned)(c)] & (CT_UP | CT_LOW | CT_DIG))
+#define isalpha(c)	((g_ctype + 1)[(unsigned)(c)] & (CT_UP | CT_LOW))
+#define iscntrl(c)	((g_ctype + 1)[(unsigned)(c)] & (CT_CTL))
+#define isdigit(c)	((g_ctype + 1)[(unsigned)(c)] & (CT_DIG))
+#define isgraph(c)	((g_ctype + 1)[(unsigned)(c)] & (CT_PUN | CT_UP | CT_LOW | CT_DIG))
+#define islower(c)	((g_ctype + 1)[(unsigned)(c)] & (CT_LOW))
+#define isprint(c)	((g_ctype + 1)[(unsigned)(c)] & (CT_PUN | CT_UP | CT_LOW | CT_DIG | CT_SP))
+#define ispunct(c)	((g_ctype + 1)[(unsigned)(c)] & (CT_PUN))
+#define isspace(c)	((g_ctype + 1)[(unsigned)(c)] & (CT_WHT))
+#define isupper(c)	((g_ctype + 1)[(unsigned)(c)] & (CT_UP))
+#define isxdigit(c)	((g_ctype + 1)[(unsigned)(c)] & (CT_DIG | CT_HEX))
+#define isascii(c)	((unsigned)(c) <= 0x7F)
+#define toascii(c)	((unsigned)(c) & 0x7F)
+
+#define tolower(c)	(isupper(c) ? c + 'a' - 'A' : c)
+#define toupper(c)	(islower(c) ? c + 'A' - 'a' : c)
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif