diff --git a/src/libs/vwidgets/vplaintextedit.cpp b/src/libs/vwidgets/vplaintextedit.cpp
index 1532ac768..98897afe2 100644
--- a/src/libs/vwidgets/vplaintextedit.cpp
+++ b/src/libs/vwidgets/vplaintextedit.cpp
@@ -27,6 +27,8 @@
  *************************************************************************/
 #include "vplaintextedit.h"
 
+#include <ciso646>
+
 //---------------------------------------------------------------------------------------------------------------------
 VPlainTextEdit::VPlainTextEdit(QWidget * parent)
     : QPlainTextEdit(parent),