diff --git a/module/zfs/spa.c b/module/zfs/spa.c
index bc2d1e1c4..29c1d4ddf 100644
--- a/module/zfs/spa.c
+++ b/module/zfs/spa.c
@@ -1683,6 +1683,7 @@ spa_activate(spa_t *spa, spa_mode_t mode)
 	ASSERT(spa->spa_state == POOL_STATE_UNINITIALIZED);
 
 	spa->spa_state = POOL_STATE_ACTIVE;
+	spa->spa_final_txg = UINT64_MAX;
 	spa->spa_mode = mode;
 	spa->spa_read_spacemaps = spa_mode_readable_spacemaps;
 
@@ -2085,6 +2086,11 @@ spa_unload(spa_t *spa)
 			vdev_rebuild_stop_all(spa);
 			l2arc_spa_rebuild_stop(spa);
 		}
+
+		spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
+		spa->spa_final_txg = spa_last_synced_txg(spa) +
+		    TXG_DEFER_SIZE + 1;
+		spa_config_exit(spa, SCL_ALL, FTAG);
 	}
 
 	/*