diff --git a/sys/sys/swap.h b/sys/sys/swap.h
index 3b2e1a6453aa..6f97eeef7e30 100644
--- a/sys/sys/swap.h
+++ b/sys/sys/swap.h
@@ -1,4 +1,4 @@
-/*	$NetBSD: swap.h,v 1.5 2000/11/17 11:32:55 mrg Exp $	*/
+/*	$NetBSD: swap.h,v 1.6 2006/08/22 14:07:07 martin Exp $	*/
 
 /*
  * Copyright (c) 1995, 1996, 1998 Matthew R. Green
@@ -65,6 +65,7 @@ struct swapent {
 #define SWAP_STATS	6		/* get device info */
 #define SWAP_DUMPDEV	7		/* use this device as dump device */
 #define SWAP_GETDUMPDEV	8		/* use this device as dump device */
+#define SWAP_DUMPOFF	9		/* stop using the dump device */
 
 #define SWF_INUSE	0x00000001	/* in use: we have swapped here */
 #define SWF_ENABLE	0x00000002	/* enabled: we can swap here */
diff --git a/sys/uvm/uvm_swap.c b/sys/uvm/uvm_swap.c
index c4dad292c8d6..9d941f557ea0 100644
--- a/sys/uvm/uvm_swap.c
+++ b/sys/uvm/uvm_swap.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: uvm_swap.c,v 1.103 2006/07/21 16:48:54 ad Exp $	*/
+/*	$NetBSD: uvm_swap.c,v 1.104 2006/08/22 14:07:07 martin Exp $	*/
 
 /*
  * Copyright (c) 1995, 1996, 1997 Matthew R. Green
@@ -32,7 +32,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: uvm_swap.c,v 1.103 2006/07/21 16:48:54 ad Exp $");
+__KERNEL_RCSID(0, "$NetBSD: uvm_swap.c,v 1.104 2006/08/22 14:07:07 martin Exp $");
 
 #include "fs_nfs.h"
 #include "opt_uvmhist.h"
@@ -512,6 +512,13 @@ sys_swapctl(struct lwp *l, void *v, register_t *retval)
 	    &l->l_acflag)))
 		goto out;
 
+	if (SCARG(uap, cmd) == SWAP_DUMPOFF) {
+		/* drop the current dump device */
+		dumpdev = NODEV;
+		cpu_dumpconf();
+		goto out;
+	}
+
 	/*
 	 * at this point we expect a path name in arg.   we will
 	 * use namei() to gain a vnode reference (vref), and lock