diff --git a/src/openttd.cpp b/src/openttd.cpp
index 6f82d168bf..0fab8cae7c 100644
--- a/src/openttd.cpp
+++ b/src/openttd.cpp
@@ -84,7 +84,7 @@
 
 #include <mutex>
 #if defined(__MINGW32__)
-#include "../3rdparty/mingw-std-threads/mingw.mutex.h"
+#include "3rdparty/mingw-std-threads/mingw.mutex.h"
 #endif
 
 #include <stdarg.h>