diff --git a/src/Gui/OnlineDocumentation.cpp b/src/Gui/OnlineDocumentation.cpp
index ac8c086be3..68aebf38b5 100644
--- a/src/Gui/OnlineDocumentation.cpp
+++ b/src/Gui/OnlineDocumentation.cpp
@@ -23,6 +23,7 @@
 
 #include "PreCompiled.h"
 #ifndef _PreComp_
+# include <QApplication>
 # include <QBuffer>
 # include <QImageWriter>
 # include <QMessageBox>