diff --git a/sys/kern/vfs_aio.c b/sys/kern/vfs_aio.c
index 8795e415ec88..ef6e3058fcab 100644
--- a/sys/kern/vfs_aio.c
+++ b/sys/kern/vfs_aio.c
@@ -1120,7 +1120,7 @@ aio_qphysio(struct proc *p, struct aiocblist *aiocbe)
 
 	s = splbio();
 	aiocbe->bp = bp;
-	bp->b_spc = (void *)aiocbe;
+	bp->b_caller2 = (void *)aiocbe;
 	TAILQ_INSERT_TAIL(&aio_bufjobs, aiocbe, list);
 	TAILQ_INSERT_TAIL(&ki->kaio_bufqueue, aiocbe, plist);
 	aiocbe->jobstate = JOBST_JOBQBUF;
@@ -2128,7 +2128,7 @@ aio_physwakeup(struct buf *bp)
 
 	wakeup(bp);
 
-	aiocbe = (struct aiocblist *)bp->b_spc;
+	aiocbe = (struct aiocblist *)bp->b_caller2;
 	if (aiocbe) {
 		p = bp->b_caller1;
 
diff --git a/sys/sys/buf.h b/sys/sys/buf.h
index f17fddb36ead..196e8f036996 100644
--- a/sys/sys/buf.h
+++ b/sys/sys/buf.h
@@ -106,6 +106,7 @@ struct buf {
 #define	b_bcount	b_io.bio_bcount
 #define	b_blkno		b_io.bio_blkno
 #define	b_caller1	b_io.bio_caller1
+#define	b_caller2	b_io.bio_caller2
 #define	b_data		b_io.bio_data
 #define	b_dev		b_io.bio_dev
 #define	b_driver1	b_io.bio_driver1
@@ -143,7 +144,6 @@ struct buf {
 	struct	ucred *b_wcred;		/* Write credentials reference. */
 	void	*b_saveaddr;		/* Original b_addr for physio. */
 	union	pager_info {
-		void	*pg_spc;
 		int	pg_reqpage;
 	} b_pager;
 	union	cluster_info {
@@ -155,8 +155,6 @@ struct buf {
 	struct	workhead b_dep;		/* (D) List of filesystem dependencies. */
 };
 
-#define b_spc	b_pager.pg_spc
-
 /*
  * These flags are kept in b_flags.
  *