diff --git a/src/threading/MsgThread.cc b/src/threading/MsgThread.cc
index 0bc3fa3901..87b4cf5677 100644
--- a/src/threading/MsgThread.cc
+++ b/src/threading/MsgThread.cc
@@ -202,7 +202,9 @@ Message::~Message()
 
 MsgThread::MsgThread() : BasicThread(), queue_in(this, nullptr), queue_out(nullptr, this)
 	{
-	cnt_sent_in = cnt_sent_out = 0;
+	cnt_sent_in.store(0);
+	cnt_sent_out.store(0);
+
 	main_finished = false;
 	child_finished = false;
 	child_sent_finish = false;
@@ -457,8 +459,8 @@ void MsgThread::Run()
 
 void MsgThread::GetStats(Stats* stats)
 	{
-	stats->sent_in = cnt_sent_in;
-	stats->sent_out = cnt_sent_out;
+	stats->sent_in = cnt_sent_in.load();
+	stats->sent_out = cnt_sent_out.load();
 	stats->pending_in = queue_in.Size();
 	stats->pending_out = queue_out.Size();
 	queue_in.GetStats(&stats->queue_in_stats);
diff --git a/src/threading/MsgThread.h b/src/threading/MsgThread.h
index 155fbb6ae4..5ab5b60ddd 100644
--- a/src/threading/MsgThread.h
+++ b/src/threading/MsgThread.h
@@ -1,5 +1,7 @@
 #pragma once
 
+#include <atomic>
+
 #include "zeek/DebugLogger.h"
 #include "zeek/threading/BasicThread.h"
 #include "zeek/threading/Queue.h"
@@ -335,8 +337,8 @@ private:
 	Queue<BasicInputMessage *> queue_in;
 	Queue<BasicOutputMessage *> queue_out;
 
-	uint64_t cnt_sent_in;	// Counts message sent to child.
-	uint64_t cnt_sent_out;	// Counts message sent by child.
+	std::atomic<uint64_t> cnt_sent_in;	// Counts message sent to child.
+	std::atomic<uint64_t> cnt_sent_out;	// Counts message sent by child.
 
 	bool main_finished;	// Main thread is finished, meaning child_finished propagated back through message queue.
 	bool child_finished;	// Child thread is finished.