diff --git a/commands/partition.c b/commands/partition.c
index f8257222a..44b91d1a1 100644
--- a/commands/partition.c
+++ b/commands/partition.c
@@ -59,11 +59,11 @@ static int mtd_part_do_parse_one(char *devname, const char *partstr,
 		size = SIZE_REMAINING;
 		end = (char *)partstr + 1;
 	} else {
-		size = strtoul_suffix(partstr, &end, 0);
+		size = strtoull_suffix(partstr, &end, 0);
 	}
 
 	if (*end == '@')
-		*offset = strtoul_suffix(end+1, &end, 0);
+		*offset = strtoull_suffix(end+1, &end, 0);
 
 	if (size == SIZE_REMAINING)
 		size = devsize - *offset;
diff --git a/drivers/mtd/partition.c b/drivers/mtd/partition.c
index 351c5831b..720c2adab 100644
--- a/drivers/mtd/partition.c
+++ b/drivers/mtd/partition.c
@@ -75,8 +75,8 @@ static int mtd_part_block_markbad(struct mtd_info *mtd, loff_t ofs)
 	return res;
 }
 
-struct mtd_info *mtd_add_partition(struct mtd_info *mtd, off_t offset, size_t size,
-		unsigned long flags, const char *name)
+struct mtd_info *mtd_add_partition(struct mtd_info *mtd, off_t offset,
+		uint64_t size, unsigned long flags, const char *name)
 {
 	struct mtd_info *part;
 	int start = 0, end = 0, i;
diff --git a/include/linux/mtd/mtd.h b/include/linux/mtd/mtd.h
index 970cdb02f..c63b514f4 100644
--- a/include/linux/mtd/mtd.h
+++ b/include/linux/mtd/mtd.h
@@ -280,8 +280,8 @@ struct mtd_notifier {
 	struct list_head list;
 };
 
-struct mtd_info *mtd_add_partition(struct mtd_info *mtd, off_t offset, size_t size,
-		unsigned long flags, const char *name);
+struct mtd_info *mtd_add_partition(struct mtd_info *mtd, off_t offset,
+		uint64_t size, unsigned long flags, const char *name);
 int mtd_del_partition(struct mtd_info *mtd);
 
 extern void register_mtd_user (struct mtd_notifier *new);