diff --git a/services/audioflinger/Threads.cpp b/services/audioflinger/Threads.cpp
index 5197d41..a555ebf 100644
--- a/services/audioflinger/Threads.cpp
+++ b/services/audioflinger/Threads.cpp
@@ -8635,6 +8635,7 @@
 
 void AudioFlinger::RecordThread::updateOutDevices(const DeviceDescriptorBaseVector& outDevices)
 {
+    Mutex::Autolock _l(mLock);
     mOutDevices = outDevices;
     mOutDeviceTypeAddrs = deviceTypeAddrsFromDescriptors(mOutDevices);
     for (size_t i = 0; i < mEffectChains.size(); i++) {