diff --git a/libs/gui/BufferQueueConsumer.cpp b/libs/gui/BufferQueueConsumer.cpp
index 525938e..96f7829 100644
--- a/libs/gui/BufferQueueConsumer.cpp
+++ b/libs/gui/BufferQueueConsumer.cpp
@@ -714,6 +714,7 @@
 }
 
 sp<NativeHandle> BufferQueueConsumer::getSidebandStream() const {
+    Mutex::Autolock lock(mCore->mMutex);
     return mCore->mSidebandStream;
 }