diff --git a/sheets/plugins/calendar/CalendarToolWidget.cpp b/sheets/plugins/calendar/CalendarToolWidget.cpp
--- a/sheets/plugins/calendar/CalendarToolWidget.cpp
+++ b/sheets/plugins/calendar/CalendarToolWidget.cpp
@@ -31,6 +31,8 @@
 
 #include <QPushButton>
 
+#include <QDate>
+
 namespace Calligra
 {
 namespace Sheets