client-tracker-announcer.go | 6 +++++-
 t.go                        | 6 ++++++
 torrent.go                  | 5 +++++

diff --git a/client-tracker-announcer.go b/client-tracker-announcer.go
index a36e12b7fdaa1867f9c79b0d7abe3d40df97dadc..f374740d671d3c295839e9f3e0268569f29cf581 100644
--- a/client-tracker-announcer.go
+++ b/client-tracker-announcer.go
@@ -380,6 +380,10 @@ 	if me.announceData.ContainsKey(key) {
 		return
 	}
 	t := me.torrentFromShortInfohash(key.ShortInfohash)
+	if t == nil {
+		// Crude, but the torrent was already dropped. We probably called AddTrackers late.
+		return
+	}
 	g.MakeMapIfNil(&me.torrentForAnnounceRequests)
 	// This can be duplicated when there's multiple trackers for a short infohash. That's fine.
 	me.torrentForAnnounceRequests[key.ShortInfohash] = weak.Make(t)
@@ -630,7 +634,7 @@ func (me *regularTrackerAnnounceDispatcher) makeTorrentInput(t *Torrent) (_ g.Option[nextAnnounceTorrentInput]) {
 	// No torrent means the client has lost interest and the dispatcher just does followup actions.
 	// If we drop a torrent, we still end up here but with a torrent that should result in None, so
 	// check for that.
-	if t == nil || !g.MapContains(me.torrentClient.torrents, t) {
+	if t == nil || t.isDropped() {
 		return
 	}
 	return g.Some(nextAnnounceTorrentInput{
diff --git a/t.go b/t.go
index ceea328ad0a409a7d3b91e27546efd50bfc28171..82dffe1436a0a7548a64bbc26ac8336437566fc0 100644
--- a/t.go
+++ b/t.go
@@ -6,6 +6,7 @@ 	"strconv"
 	"strings"
 
 	"github.com/anacrolix/chansync/events"
+	g "github.com/anacrolix/generics"
 	"github.com/anacrolix/missinggo/v2/pubsub"
 	"github.com/anacrolix/sync"
 
@@ -303,3 +304,8 @@ 		ret = append(ret, &c.peer)
 	}
 	return ret
 }
+
+// Was dropped from the Client.
+func (t *Torrent) isDropped() bool {
+	return !g.MapContains(t.cl.torrents, t)
+}
diff --git a/torrent.go b/torrent.go
index f39ef04209b9aed4e91f694d0725b001eff68160..893814b9d5a3b98b1cfe847b3e77fa1d92f3cfe4 100644
--- a/torrent.go
+++ b/torrent.go
@@ -1917,6 +1917,11 @@ 	return
 }
 
 func (t *Torrent) addTrackers(announceList [][]string) {
+	if t.isDropped() {
+		// Can't alter dropped Torrent because it may have skipped registering announce states with
+		// the announce dispatcher.
+		return
+	}
 	fullAnnounceList := &t.announceList
 	t.announceList = appendMissingTrackerTiers(*fullAnnounceList, len(announceList))
 	for tierIndex, trackerURLs := range announceList {