diff --git a/fb.h b/fb.h
index 7469fb6..bcde8b8 100644
--- a/fb.h
+++ b/fb.h
@@ -1,5 +1,5 @@
-#ifndef INCLUDE_IO_H
-#define INCLUDE_IO_H
+#ifndef INCLUDE_FRAMEBUFFER
+#define INCLUDE_FRAMEBUFFER
 
 /* The I/O ports */
 #define FB_COMMAND_PORT 0x3D4
@@ -11,7 +11,7 @@
 
 int write(char *buf, unsigned int len);
 
-extern void outb(unsigned short port, unsigned char data);
+
 
 /** fb_write_cell:
     *  Writes a character with the given foreground and background to position i
diff --git a/io.h b/io.h
new file mode 100644
index 0000000..9f20745
--- /dev/null
+++ b/io.h
@@ -0,0 +1,20 @@
+#ifndef INCLUDE_IO
+#define INCLUDE_IO
+
+
+/** outb
+ * Write bytes to an I/O port.
+ * 
+ * @param port The address of the I/O port
+ */
+extern void outb(unsigned short port, unsigned char data);
+
+/** inb:
+ *  Read a byte from an I/O port.
+ *
+ *  @param  port The address of the I/O port
+ *  @return      The read byte
+ */
+unsigned char inb(unsigned short port);
+
+#endif
\ No newline at end of file
diff --git a/kmain.h b/kmain.h
index ec107a6..a8b2b1d 100644
--- a/kmain.h
+++ b/kmain.h
@@ -1 +1,6 @@
-int main();
\ No newline at end of file
+#ifndef INCLUDE_MAIN
+#define INCLUDE_MAIN
+
+int main();
+
+#endif
\ No newline at end of file