diff --git a/hscontrol/mapper/batcher.go b/hscontrol/mapper/batcher.go
index 1d9dc924..d16949e0 100644
--- a/hscontrol/mapper/batcher.go
+++ b/hscontrol/mapper/batcher.go
@@ -185,6 +185,10 @@ var (
 
 // Batcher batches and distributes map responses to connected nodes.
 // It uses concurrent maps, per-node mutexes, and a worker pool.
+//
+// Lifecycle: Call Start() to spawn workers, then Close() to shut down.
+// Close() blocks until all workers have exited. A Batcher must not
+// be reused after Close().
 type Batcher struct {
 	tick    *time.Ticker
 	mapper  *mapper
@@ -198,6 +202,10 @@ type Batcher struct {
 	done     chan struct{}
 	doneOnce sync.Once // Ensures done is only closed once
 
+	// wg tracks the doWork and all worker goroutines so that Close()
+	// can block until they have fully exited.
+	wg sync.WaitGroup
+
 	started atomic.Bool // Ensures Start() is only called once
 
 	// Metrics
@@ -329,6 +337,8 @@ func (b *Batcher) Start() {
 
 	b.done = make(chan struct{})
 
+	b.wg.Add(1)
+
 	go b.doWork()
 }
 
@@ -344,6 +354,14 @@ func (b *Batcher) Close() {
 		}
 	})
 
+	// Wait for all worker goroutines (and doWork) to exit before
+	// tearing down node connections. This prevents workers from
+	// sending on connections that are being closed concurrently.
+	b.wg.Wait()
+
+	// Stop the ticker to prevent resource leaks.
+	b.tick.Stop()
+
 	// Close the underlying channels supplying the data to the clients.
 	b.nodes.Range(func(nodeID types.NodeID, conn *multiChannelNodeConn) bool {
 		if conn == nil {
@@ -357,7 +375,11 @@ func (b *Batcher) Close() {
 }
 
 func (b *Batcher) doWork() {
+	defer b.wg.Done()
+
 	for i := range b.workers {
+		b.wg.Add(1)
+
 		go b.worker(i + 1)
 	}
 
@@ -381,6 +403,8 @@ func (b *Batcher) doWork() {
 }
 
 func (b *Batcher) worker(workerID int) {
+	defer b.wg.Done()
+
 	wlog := log.With().Int(zf.WorkerID, workerID).Logger()
 
 	for {