diff --git a/drivers/mtd/nand/omap2.c b/drivers/mtd/nand/omap2.c
index 1bb799f0125c..4eea97c03b2b 100644
--- a/drivers/mtd/nand/omap2.c
+++ b/drivers/mtd/nand/omap2.c
@@ -505,7 +505,7 @@ static void omap_write_buf_dma_pref(struct mtd_info *mtd,
 		omap_write_buf_pref(mtd, buf, len);
 	else
 		/* start transfer in DMA mode */
-		omap_nand_dma_transfer(mtd, buf, len, 0x1);
+		omap_nand_dma_transfer(mtd, (u_char *) buf, len, 0x1);
 }
 
 /**