diff --git a/sys/sys/buf.h b/sys/sys/buf.h
index 7185bff6472d..9923562e19f0 100644
--- a/sys/sys/buf.h
+++ b/sys/sys/buf.h
@@ -210,7 +210,7 @@ struct buf {
 #define	B_CLUSTEROK	0x00020000	/* Pagein op, so swap() can count it. */
 #define	B_000400000	0x00040000	/* Available flag. */
 #define	B_000800000	0x00080000	/* Available flag. */
-#define	B_00100000	0x00100000	/* Available flag. */
+#define	B_001000000	0x00100000	/* Available flag. */
 #define	B_DIRTY		0x00200000	/* Needs writing later (in EXT2FS). */
 #define	B_RELBUF	0x00400000	/* Release VMIO buffer. */
 #define	B_FS_FLAG1	0x00800000	/* Available flag for FS use. */