diff --git a/fs/jfs/jfs_xtree.c b/fs/jfs/jfs_xtree.c
index 2d304cee8..900f9dc77 100644
--- a/fs/jfs/jfs_xtree.c
+++ b/fs/jfs/jfs_xtree.c
@@ -619,6 +619,8 @@ int xtInsert(tid_t tid,		/* transaction id */
 			(nextindex - index) * sizeof(xad_t));
 
 	/* insert the new entry: mark the entry NEW */
+	 if (index >= XTROOTMAXSLOT)
+	 	 return -EINVAL;
 	xad = &p->xad[index];
 	XT_PUTENTRY(xad, xflag, xoff, xlen, xaddr);
 
diff --git a/fs/jfs/jfs_xtree.h b/fs/jfs/jfs_xtree.h
index ad7592191..832e8a77d 100644
--- a/fs/jfs/jfs_xtree.h
+++ b/fs/jfs/jfs_xtree.h
@@ -61,7 +61,7 @@ struct xadlist {
 /* possible values for maxentry */
 #define XTROOTINITSLOT_DIR 6
 #define XTROOTINITSLOT	10
-#define XTROOTMAXSLOT	18
+#define XTROOTMAXSLOT	16
 #define XTPAGEMAXSLOT	256
 #define XTENTRYSTART	2