diff --git a/src/corelib/time/qcalendar.cpp b/src/corelib/time/qcalendar.cpp
index 987d30036b0..6132977c40a 100644
--- a/src/corelib/time/qcalendar.cpp
+++ b/src/corelib/time/qcalendar.cpp
@@ -55,7 +55,7 @@
 #include <qhash.h>
 #include <qdebug.h>
 
-#include <unordered_map>
+#include <vector>
 
 QT_BEGIN_NAMESPACE