diff --git a/drivers/mtd/nand/raw/nand_util.c b/drivers/mtd/nand/raw/nand_util.c
index 5b74ef0..00c3c6c 100644
--- a/drivers/mtd/nand/raw/nand_util.c
+++ b/drivers/mtd/nand/raw/nand_util.c
@@ -635,14 +635,14 @@
 	}
 
 	while (left_to_write > 0) {
+		loff_t block_start = offset & ~(loff_t)(mtd->erasesize - 1);
 		size_t block_offset = offset & (mtd->erasesize - 1);
 		size_t write_size, truncated_write_size;
 
 		WATCHDOG_RESET();
 
-		if (nand_block_isbad(mtd, offset & ~(mtd->erasesize - 1))) {
-			printf("Skip bad block 0x%08llx\n",
-				offset & ~(mtd->erasesize - 1));
+		if (nand_block_isbad(mtd, block_start)) {
+			printf("Skip bad block 0x%08llx\n", block_start);
 			offset += mtd->erasesize - block_offset;
 			continue;
 		}