diff --git a/common/cmd_elf.c b/common/cmd_elf.c
index 4a3fff1..83e7589 100644
--- a/common/cmd_elf.c
+++ b/common/cmd_elf.c
@@ -131,11 +131,11 @@
 
 #if defined(CONFIG_WALNUT)
 	tmp = (char *) CONFIG_SYS_NVRAM_BASE_ADDR + 0x500;
-	eth_getenv_enetaddr("ethaddr", build_buf);
+	eth_getenv_enetaddr("ethaddr", (uchar *)build_buf);
 	memcpy(tmp, &build_buf[3], 3);
 #elif defined(CONFIG_SYS_VXWORKS_MAC_PTR)
 	tmp = (char *) CONFIG_SYS_VXWORKS_MAC_PTR;
-	eth_getenv_enetaddr("ethaddr", build_buf);
+	eth_getenv_enetaddr("ethaddr", (uchar *)build_buf);
 	memcpy(tmp, build_buf, 6);
 #else
 	puts ("## Ethernet MAC address not copied to NV RAM\n");