diff --git a/fs/cramfs/cramfs.c b/fs/cramfs/cramfs.c
index e578a1e..fd8e4ef 100644
--- a/fs/cramfs/cramfs.c
+++ b/fs/cramfs/cramfs.c
@@ -43,9 +43,10 @@
  * device address space offset, so we need to shift it by a device start address. */
 #if !defined(CONFIG_SYS_NO_FLASH)
 extern flash_info_t flash_info[];
-#define PART_OFFSET(x)	(x->offset + flash_info[x->dev->id->num].start[0])
+#define PART_OFFSET(x)	((ulong)x->offset + \
+			 flash_info[x->dev->id->num].start[0])
 #else
-#define PART_OFFSET(x)	(x->offset)
+#define PART_OFFSET(x)	((ulong)x->offset)
 #endif
 
 static int cramfs_read_super (struct part_info *info)