From 7d221f10c195f762e07d7ea12a2992492b8ca906 Mon Sep 17 00:00:00 2001
From: wmayer <wmayer@users.sourceforge.net>
Date: Thu, 22 Dec 2022 11:01:23 +0100
Subject: [PATCH] Gui: [skip ci] fix build failure due to missing include

---
 src/Gui/Document.cpp | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/Gui/Document.cpp b/src/Gui/Document.cpp
index 6aa26fff0a..2a4f9e8d22 100644
--- a/src/Gui/Document.cpp
+++ b/src/Gui/Document.cpp
@@ -24,6 +24,7 @@
 
 #ifndef _PreComp_
 # include <cctype>
+# include <mutex>
 # include <QApplication>
 # include <QFileInfo>
 # include <QMessageBox>