diff --git a/libmaxsi/Makefile b/libmaxsi/Makefile
index 5debe31e..c3dd4b43 100644
--- a/libmaxsi/Makefile
+++ b/libmaxsi/Makefile
@@ -29,11 +29,13 @@ ASFLAGS=$(CPUASFLAGS)
 NASMFLAGS=$(CPUNASMFLAGS)
 
 COBJS=\
+c/ctype.o \
 c/file.o \
 c/fdio.o \
 c/stdio.o \
 
 CHEADERS=\
+c/h/ctype.h \
 c/h/unistd.h \
 c/h/stdlib.h \
 c/h/wchar.h \
diff --git a/libmaxsi/c/ctype.c b/libmaxsi/c/ctype.c
new file mode 100644
index 00000000..a639ac9e
--- /dev/null
+++ b/libmaxsi/c/ctype.c
@@ -0,0 +1,103 @@
+/******************************************************************************
+
+	COPYRIGHT(C) JONAS 'SORTIE' TERMANSEN 2011.
+
+	This file is part of LibMaxsi.
+
+	LibMaxsi is free software: you can redistribute it and/or modify it under
+	the terms of the GNU Lesser General Public License as published by the Free
+	Software Foundation, either version 3 of the License, or (at your option)
+	any later version.
+
+	LibMaxsi is distributed in the hope that it will be useful, but WITHOUT ANY
+	WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+	FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for
+	more details.
+
+	You should have received a copy of the GNU Lesser General Public License
+	along with LibMaxsi. If not, see <http://www.gnu.org/licenses/>.
+
+	ctype.c
+	Character types.
+
+******************************************************************************/
+
+#include <ctype.h>
+
+// TODO: Support other locales than ASCII.
+
+int isalnum(int c)
+{
+	return isalpha(c) || isdigit(c);
+}
+
+int isalpha(int c)
+{
+	return isupper(c) || islower(c);
+}
+
+int isblank(int c)
+{
+	return c == ' ' || c == '\t';
+}
+
+int iscntrl(int c)
+{
+	return 0 <= c && c < 32;
+}
+
+int isdigit(int c)
+{
+	return '0' <= c && c <= '9';
+}
+
+int isgraph(int c)
+{
+	return '!' <= c && c <= '~';
+}
+
+int islower(int c)
+{
+	return 'a' <= c && c <= 'z';
+}
+
+int isprint(int c)
+{
+	return isgraph(c) || c == ' ';
+}
+
+int ispunct(int c)
+{
+	return isprint(c) && c != ' ' && !isalnum(c);
+}
+
+int isspace(int c)
+{
+	return c == '\t' || c == '\n' || c == '\v' || c == '\f' || c == '\r' || c == ' ';
+}
+
+int isupper(int c)
+{
+	return 'A' <= c && c <= 'Z';
+}
+
+int isxdigit(int c)
+{
+	if ( isdigit(c) ) { return 1; }
+	if ( 'a' <= c && c <= 'f' ) { return 1; }
+	if ( 'A' <= c && c <= 'F' ) { return 1; }
+	return 0;
+}
+
+int tolower(int c)
+{
+	if ( 'A' <= c && c <= 'Z' ) { return 'a' + c - 'A'; }
+	return c;
+}
+
+int toupper(int c)
+{
+	if ( 'a' <= c && c <= 'z' ) { return 'A' + c - 'a'; }
+	return c;
+}
+
diff --git a/libmaxsi/c/hsrc/ctype.h b/libmaxsi/c/hsrc/ctype.h
new file mode 100644
index 00000000..619db406
--- /dev/null
+++ b/libmaxsi/c/hsrc/ctype.h
@@ -0,0 +1,53 @@
+/******************************************************************************
+
+	COPYRIGHT(C) JONAS 'SORTIE' TERMANSEN 2011.
+
+	This file is part of LibMaxsi.
+
+	LibMaxsi is free software: you can redistribute it and/or modify it under
+	the terms of the GNU Lesser General Public License as published by the Free
+	Software Foundation, either version 3 of the License, or (at your option)
+	any later version.
+
+	LibMaxsi is distributed in the hope that it will be useful, but WITHOUT ANY
+	WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+	FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for
+	more details.
+
+	You should have received a copy of the GNU Lesser General Public License
+	along with LibMaxsi. If not, see <http://www.gnu.org/licenses/>.
+
+	ctype.h
+	Character types.
+
+******************************************************************************/
+
+/* TODO: POSIX-1.2008 compliance is only partial */
+
+#ifndef	_CTYPE_H
+#define	_CTYPE_H 1
+
+#include <features.h>
+
+__BEGIN_DECLS
+
+/* TODO: Declare locale_t and the *_t functions here */
+int isalnum(int c);
+int isalpha(int c);
+int isblank(int c);
+int iscntrl(int c);
+int isdigit(int c);
+int isgraph(int c);
+int islower(int c);
+int isprint(int c);
+int ispunct(int c);
+int isspace(int c);
+int isupper(int c);
+int isxdigit(int c);
+int tolower(int c);
+int toupper(int c);
+
+__END_DECLS
+
+#endif
+