diff --git a/board/sandburst/common/ppc440gx_i2c.c b/board/sandburst/common/ppc440gx_i2c.c
index 858b38c..859dd7a 100644
--- a/board/sandburst/common/ppc440gx_i2c.c
+++ b/board/sandburst/common/ppc440gx_i2c.c
@@ -451,9 +451,9 @@
  */
 uchar i2c_reg_read1(uchar i2c_addr, uchar reg)
 {
-	char buf;
+	uchar buf;
 
-	i2c_read1(i2c_addr, reg, 1, &buf, 1);
+	i2c_read1(i2c_addr, reg, 1, &buf, (uchar)1);
 
 	return(buf);
 }