diff --git a/board/iphase4539/iphase4539.c b/board/iphase4539/iphase4539.c
index e50250e..0ca9cf5 100644
--- a/board/iphase4539/iphase4539.c
+++ b/board/iphase4539/iphase4539.c
@@ -342,7 +342,7 @@
 {
 	int sn = -1;
 
-	if (!seeprom_read (0xa0, (char *) &sn, sizeof (sn))) {
+	if (!seeprom_read (0xa0, (uchar *) &sn, sizeof (sn))) {
 		sn = cpu_to_le32 (sn);
 	}
 	return sn;
@@ -351,7 +351,7 @@
 {
 	char mac[6];
 
-	if (!seeprom_read (0xb0, mac, sizeof (mac))) {
+	if (!seeprom_read (0xb0, (uchar *)mac, sizeof (mac))) {
 		sprintf (str, "%02x:%02x:%02x:%02x:%02x:%02x\n",
 				 mac[0], mac[1], mac[2], mac[3], mac[4], mac[5]);
 	} else {