diff --git a/modules/video_capture/linux/video_capture_pipewire.cc b/modules/video_capture/linux/video_capture_pipewire.cc
index c448e94..bb1babd 100644
--- a/modules/video_capture/linux/video_capture_pipewire.cc
+++ b/modules/video_capture/linux/video_capture_pipewire.cc
@@ -177,6 +177,8 @@
 }
 
 bool VideoCaptureModulePipeWire::CaptureStarted() {
+  MutexLock lock(&api_lock_);
+
   return started_;
 }
 
@@ -294,6 +296,7 @@
       static_cast<VideoCaptureModulePipeWire*>(data);
   RTC_DCHECK(that);
 
+  MutexLock lock(&that->api_lock_);
   switch (state) {
     case PW_STREAM_STATE_STREAMING:
       that->started_ = true;
diff --git a/modules/video_capture/linux/video_capture_pipewire.h b/modules/video_capture/linux/video_capture_pipewire.h
index 5ce02d1..2cd6cca 100644
--- a/modules/video_capture/linux/video_capture_pipewire.h
+++ b/modules/video_capture/linux/video_capture_pipewire.h
@@ -46,7 +46,7 @@
   rtc::scoped_refptr<PipeWireSession> session_;
   int node_id_;
   VideoCaptureCapability configured_capability_;
-  bool started_;
+  bool started_ RTC_GUARDED_BY(api_lock_);
 
   struct pw_stream* stream_;
   struct spa_hook stream_listener_;