diff --git a/src/arch/i386/interface/syslinux/comboot_call.c b/src/arch/i386/interface/syslinux/comboot_call.c
index a78af7290..30fb49a15 100644
--- a/src/arch/i386/interface/syslinux/comboot_call.c
+++ b/src/arch/i386/interface/syslinux/comboot_call.c
@@ -326,7 +326,7 @@ static __asmcall void int22 ( struct i386_all_regs *ix86 ) {
 	case 0x0001: /* Get Version */
 
 		/* Number of INT 22h API functions available */
-		ix86->regs.ax = 0x001B;
+		ix86->regs.ax = 0x001D;
 
 		/* SYSLINUX version number */
 		ix86->regs.ch = 0; /* major */
@@ -631,6 +631,17 @@ static __asmcall void int22 ( struct i386_all_regs *ix86 ) {
 
 		break;
 
+	case 0x001C: /* Get pointer to auxilliary data vector */
+		/* FIXME: stub */
+		ix86->regs.cx = 0; /* Size of the ADV */
+		ix86->flags &= ~CF;
+		break;
+
+	case 0x001D: /* Write auxilliary data vector */
+		/* FIXME: stub */
+		ix86->flags &= ~CF;
+		break;
+
 	default:
 		DBG ( "COMBOOT unknown int22 function %04x\n", ix86->regs.ax );
 		break;