diff --git a/rtc_base/thread.cc b/rtc_base/thread.cc
index a8e89cd8f3..b20ec2d6a5 100644
--- a/rtc_base/thread.cc
+++ b/rtc_base/thread.cc
@@ -844,6 +844,7 @@ void Thread::Send(const Location& posted_from,
                   MessageHandler* phandler,
                   uint32_t id,
                   MessageData* pdata) {
+  RTC_DCHECK(!IsQuitting());
   if (IsQuitting())
     return;