diff --git a/src/engine/platform/pcspkr.h b/src/engine/platform/pcspkr.h
index b2a88b903..b1a394444 100644
--- a/src/engine/platform/pcspkr.h
+++ b/src/engine/platform/pcspkr.h
@@ -23,7 +23,6 @@
 #include "../dispatch.h"
 #include "../../fixedQueue.h"
 #include <thread>
-#include <mutex>
 #include <condition_variable>
 
 class DivPlatformPCSpeaker: public DivDispatch {
diff --git a/src/engine/workPool.h b/src/engine/workPool.h
index 17e4be52a..ec12843aa 100644
--- a/src/engine/workPool.h
+++ b/src/engine/workPool.h
@@ -21,7 +21,6 @@
 #define _WORKPOOL_H
 
 #include <thread>
-#include <mutex>
 #include <atomic>
 #include <functional>
 #include <future>