diff --git a/include/common.h b/include/common.h
index bd4ec38..fef2007 100644
--- a/include/common.h
+++ b/include/common.h
@@ -1,8 +1,6 @@
 #ifndef __COMMON_H
 #define __COMMON_H
 #include "font.h"
-#include <stdio.h>
-#include <stdarg.h>
 
 void io_hlt(void);
 void io_cli(void);
diff --git a/lib/ctype.h b/include/ctype.h
similarity index 100%
rename from lib/ctype.h
rename to include/ctype.h
diff --git a/include/string.h b/include/string.h
new file mode 100644
index 0000000..8a945ab
--- /dev/null
+++ b/include/string.h
@@ -0,0 +1,9 @@
+
+#ifndef _STRING_H
+#define _STRING_H
+#include "ctype.h"
+
+#define NULL 0ULL
+size_t strnlen(const char *s, size_t maxlen);
+int strncmp(const char *s1, const char *s2, size_t n);
+#endif