diff --git a/dhcp.c b/dhcp.c
index 9febcca..67c0e50 100644
--- a/dhcp.c
+++ b/dhcp.c
@@ -82,7 +82,7 @@ struct dhcp_pkt {
 __xdata uint32_t long_value;
 
 
-void dhcp_print_ip(uint8_t *a)
+void dhcp_print_ip(__xdata uint8_t *a)
 {
 	itoa(a[0]); write_char('.');
 	itoa(a[1]); write_char('.');