diff --git a/src/arch/i386/drivers/net/undinet.c b/src/arch/i386/drivers/net/undinet.c
index 56bd6288..5cfceda7 100644
--- a/src/arch/i386/drivers/net/undinet.c
+++ b/src/arch/i386/drivers/net/undinet.c
@@ -558,8 +558,10 @@ int undinet_probe ( struct undi_device *undi ) {
 	DBGC ( undinic, "UNDINIC %p has type %s, speed %d, flags %08x\n",
 	       undinic, undi_iface.IfaceType, undi_iface.LinkSpeed,
 	       undi_iface.ServiceFlags );
-	if ( undi_iface.ServiceFlags & SUPPORTED_IRQ )
+	if ( ( undi_iface.ServiceFlags & SUPPORTED_IRQ ) &&
+	     ( undinic->irq != 0 ) ) {
 		undinic->irq_supported = 1;
+	}
 	DBGC ( undinic, "UNDINIC %p using %s mode\n", undinic,
 	       ( undinic->irq_supported ? "interrupt" : "polling" ) );
 	if ( strncmp ( ( ( char * ) undi_iface.IfaceType ), "Etherboot",