diff --git a/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/vdev.c b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/vdev.c
index f6d284023340..6d39389ec79b 100644
--- a/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/vdev.c
+++ b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/vdev.c
@@ -22,7 +22,7 @@
 /*
  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
  * Copyright (c) 2011, 2015 by Delphix. All rights reserved.
- * Copyright 2015 Nexenta Systems, Inc.  All rights reserved.
+ * Copyright 2017 Nexenta Systems, Inc.
  * Copyright 2013 Martin Matuska <mm@FreeBSD.org>. All rights reserved.
  * Copyright (c) 2014 Integros [integros.com]
  * Copyright 2016 Toomas Soome <tsoome@me.com>
@@ -2595,7 +2595,8 @@ int
 vdev_online(spa_t *spa, uint64_t guid, uint64_t flags, vdev_state_t *newstate)
 {
 	vdev_t *vd, *tvd, *pvd, *rvd = spa->spa_root_vdev;
-	boolean_t postevent = B_FALSE;
+	boolean_t wasoffline;
+	vdev_state_t oldstate;
 
 	spa_vdev_state_enter(spa, SCL_NONE);
 
@@ -2605,9 +2606,8 @@ vdev_online(spa_t *spa, uint64_t guid, uint64_t flags, vdev_state_t *newstate)
 	if (!vd->vdev_ops->vdev_op_leaf)
 		return (spa_vdev_state_exit(spa, NULL, ENOTSUP));
 
-	postevent =
-	    (vd->vdev_offline == B_TRUE || vd->vdev_tmpoffline == B_TRUE) ?
-	    B_TRUE : B_FALSE;
+	wasoffline = (vd->vdev_offline || vd->vdev_tmpoffline);
+	oldstate = vd->vdev_state;
 
 	tvd = vd->vdev_top;
 	vd->vdev_offline = B_FALSE;
@@ -2645,7 +2645,9 @@ vdev_online(spa_t *spa, uint64_t guid, uint64_t flags, vdev_state_t *newstate)
 		spa_async_request(spa, SPA_ASYNC_CONFIG_UPDATE);
 	}
 
-	if (postevent)
+	if (wasoffline ||
+	    (oldstate < VDEV_STATE_DEGRADED &&
+	    vd->vdev_state >= VDEV_STATE_DEGRADED))
 		spa_event_notify(spa, vd, ESC_ZFS_VDEV_ONLINE);
 
 	return (spa_vdev_state_exit(spa, vd, 0));