diff --git a/barnard.go b/barnard.go
index b57d300..f794710 100644
--- a/barnard.go
+++ b/barnard.go
@@ -31,11 +31,12 @@ type Barnard struct {
 	Address   string
 	TLSConfig tls.Config
 
-	Stream       *gumbleopenal.Stream
-	Tx           bool
-	AutoTransmit bool // auto-start transmission on connect
-	Connected    bool
-	stateMutex   sync.RWMutex
+	Stream          *gumbleopenal.Stream
+	connectionMutex sync.RWMutex
+	Tx              bool
+	AutoTransmit    bool // auto-start transmission on connect
+	Connected       bool
+	stateMutex      sync.RWMutex
 
 	Ui                *uiterm.Ui
 	UiOutput          uiterm.Textview
@@ -96,11 +97,13 @@ type Barnard struct {
 // reconnect replaces them. It is intentionally idempotent for repeated
 // disconnect notifications.
 func (b *Barnard) cleanupConnectionAudio() {
+	b.connectionMutex.Lock()
 	if b.Stream != nil {
 		stream := b.Stream
 		b.Stream = nil
 		stream.Destroy()
 	}
+	b.connectionMutex.Unlock()
 	b.FileStreamMutex.Lock()
 	if b.FileStream != nil {
 		_ = b.FileStream.Stop()
@@ -121,9 +124,21 @@ func (b *Barnard) cleanupToneTestAudio() {
 }
 
 func (b *Barnard) updateUserGain(user *gumble.User) {
-	if b.Stream != nil {
-		b.Stream.UpdateUserGain(user)
+	b.withStream(func(stream *gumbleopenal.Stream) {
+		stream.UpdateUserGain(user)
+	})
+}
+
+// withStream keeps a connection-owned stream alive for the complete operation.
+// Reconnect cleanup takes the write lock before destroying or replacing it.
+func (b *Barnard) withStream(action func(*gumbleopenal.Stream)) bool {
+	b.connectionMutex.RLock()
+	defer b.connectionMutex.RUnlock()
+	if b.Stream == nil {
+		return false
 	}
+	action(b.Stream)
+	return true
 }
 
 func (b *Barnard) isChannelMuted(channelID uint32) bool {
@@ -212,8 +227,8 @@ func (b *Barnard) StopTransmission() {
 				close(b.toneTestStop)
 				b.toneTestStop = nil
 			}
-		} else if b.Stream != nil {
-			b.Stream.StopSource()
+		} else {
+			b.withStream(func(stream *gumbleopenal.Stream) { _ = stream.StopSource() })
 		}
 	}
 }
diff --git a/client.go b/client.go
index c50845c..4b7696a 100644
--- a/client.go
+++ b/client.go
@@ -87,11 +87,10 @@ func (b *Barnard) connect(reconnect bool) bool {
 		b.exitWithError(err)
 		return false
 	}
-	b.Stream = stream
-	b.Stream.SetMicVolume(b.UserConfig.GetMicVolume(), false)
-	b.Stream.AttachStream(b.Client)
-	b.Stream.SetNoiseProcessor(b.NoiseSuppressor)
-	b.Stream.SetErrorFunc(func(err error) {
+	stream.SetMicVolume(b.UserConfig.GetMicVolume(), false)
+	stream.AttachStream(b.Client)
+	stream.SetNoiseProcessor(b.NoiseSuppressor)
+	stream.SetErrorFunc(func(err error) {
 		if err != nil {
 			b.AddOutputLine(fmt.Sprintf("Microphone: %s", err.Error()))
 		} else {
@@ -110,8 +109,11 @@ func (b *Barnard) connect(reconnect bool) bool {
 		b.Client.DisableStereoEncoder()
 		b.AddOutputLine(fmt.Sprintf("File playback: %s", err.Error()))
 	})
-	b.Stream.SetFilePlayer(b.FileStream)
+	stream.SetFilePlayer(b.FileStream)
 	b.FileStreamMutex.Unlock()
+	b.connectionMutex.Lock()
+	b.Stream = stream
+	b.connectionMutex.Unlock()
 
 	b.setConnected(true)
 	// Dial delivers OnConnect before connect creates the OpenAL stream, so
@@ -166,16 +168,21 @@ func (b *Barnard) OnConnect(e *gumble.ConnectEvent) {
 }
 
 func (b *Barnard) startAutoTransmit() {
-	if !b.AutoTransmit || b.Stream == nil || b.isTransmitting() {
+	if !b.AutoTransmit || b.isTransmitting() {
 		return
 	}
-	if err := b.Stream.StartSource(b.UserConfig.GetInputDevice()); err != nil {
-		b.AddOutputLine(fmt.Sprintf("auto-transmit failed: %s", err.Error()))
+	started := b.withStream(func(stream *gumbleopenal.Stream) {
+		if err := stream.StartSource(b.UserConfig.GetInputDevice()); err != nil {
+			b.AddOutputLine(fmt.Sprintf("auto-transmit failed: %s", err.Error()))
+			return
+		}
+		b.setTransmitting(true)
+		b.UpdateGeneralStatus(" AutoTx ", true)
+		b.AddOutputLine("Auto-transmit started")
+	})
+	if !started {
 		return
 	}
-	b.setTransmitting(true)
-	b.UpdateGeneralStatus(" AutoTx ", true)
-	b.AddOutputLine("Auto-transmit started")
 }
 
 func (b *Barnard) OnDisconnect(e *gumble.DisconnectEvent) {
diff --git a/connection_resource_test.go b/connection_resource_test.go
new file mode 100644
index 0000000..5415eae
--- /dev/null
+++ b/connection_resource_test.go
@@ -0,0 +1,13 @@
+package main
+
+import (
+	"testing"
+
+	"git.stormux.org/storm/barnard/gumble/gumbleopenal"
+)
+
+func TestWithStreamHandlesAbsentConnectionResource(t *testing.T) {
+	if (&Barnard{}).withStream(func(*gumbleopenal.Stream) {}) {
+		t.Fatal("nil connection stream was treated as available")
+	}
+}