diff --git a/autotests/testincidence.cpp b/autotests/testincidence.cpp
--- a/autotests/testincidence.cpp
+++ b/autotests/testincidence.cpp
@@ -20,7 +20,6 @@
 */
 #include "testincidence.h"
 #include "event.h"
-#include "utils.h"
 
 #include <QTest>
 
diff --git a/autotests/testmemorycalendar.cpp b/autotests/testmemorycalendar.cpp
--- a/autotests/testmemorycalendar.cpp
+++ b/autotests/testmemorycalendar.cpp
@@ -22,7 +22,6 @@
 #include "testmemorycalendar.h"
 #include "filestorage.h"
 #include "memorycalendar.h"
-#include "utils.h"
 
 #include <QDebug>
 
diff --git a/autotests/testperiod.cpp b/autotests/testperiod.cpp
--- a/autotests/testperiod.cpp
+++ b/autotests/testperiod.cpp
@@ -23,7 +23,7 @@
 
 #include "testperiod.h"
 #include "period.h"
-#include "utils.h"
+#include "utils_p.h"
 
 #include <QTest>
 QTEST_MAIN(PeriodTest)
diff --git a/autotests/testrecurprevious.cpp b/autotests/testrecurprevious.cpp
--- a/autotests/testrecurprevious.cpp
+++ b/autotests/testrecurprevious.cpp
@@ -22,7 +22,6 @@
 
 #include "filestorage.h"
 #include "memorycalendar.h"
-#include "utils.h"
 
 #include <QDebug>
 #include <QFile>
diff --git a/autotests/testrecurson.cpp b/autotests/testrecurson.cpp
--- a/autotests/testrecurson.cpp
+++ b/autotests/testrecurson.cpp
@@ -22,7 +22,6 @@
 
 #include "filestorage.h"
 #include "memorycalendar.h"
-#include "utils.h"
 
 #include <QDebug>
 #include <QDate>
diff --git a/autotests/testrecurtodo.cpp b/autotests/testrecurtodo.cpp
--- a/autotests/testrecurtodo.cpp
+++ b/autotests/testrecurtodo.cpp
@@ -20,7 +20,6 @@
 */
 #include "testrecurtodo.h"
 #include "todo.h"
-#include "utils.h"
 
 #include <QDebug>
 #include <QTest>
diff --git a/autotests/testtimesininterval.cpp b/autotests/testtimesininterval.cpp
--- a/autotests/testtimesininterval.cpp
+++ b/autotests/testtimesininterval.cpp
@@ -21,7 +21,6 @@
 */
 #include "testtimesininterval.h"
 #include "event.h"
-#include "utils.h"
 
 #include <QDebug>
 
diff --git a/autotests/testtodo.cpp b/autotests/testtodo.cpp
--- a/autotests/testtodo.cpp
+++ b/autotests/testtodo.cpp
@@ -22,7 +22,6 @@
 #include "todo.h"
 #include "event.h"
 #include "attachment.h"
-#include "utils.h"
 
 #include <QTest>
 QTEST_MAIN(TodoTest)
diff --git a/src/alarm.cpp b/src/alarm.cpp
--- a/src/alarm.cpp
+++ b/src/alarm.cpp
@@ -33,7 +33,7 @@
 #include "alarm.h"
 #include "duration.h"
 #include "incidence.h"
-#include "utils.h"
+#include "utils_p.h"
 
 #include <QTime>
 #include <QTimeZone>
diff --git a/src/calendar.cpp b/src/calendar.cpp
--- a/src/calendar.cpp
+++ b/src/calendar.cpp
@@ -40,7 +40,6 @@
 #include "icaltimezones_p.h"
 #include "sorting.h"
 #include "visitor.h"
-#include "utils.h"
 
 #include "kcalcore_debug.h"
 
diff --git a/src/compat.cpp b/src/compat.cpp
--- a/src/compat.cpp
+++ b/src/compat.cpp
@@ -34,7 +34,6 @@
 
 #include "compat_p.h"
 #include "incidence.h"
-#include "utils.h"
 
 #include "kcalcore_debug.h"
 
diff --git a/src/event.cpp b/src/event.cpp
--- a/src/event.cpp
+++ b/src/event.cpp
@@ -31,7 +31,7 @@
 
 #include "event.h"
 #include "visitor.h"
-#include "utils.h"
+#include "utils_p.h"
 #include "kcalcore_debug.h"
 
 #include <QDate>
diff --git a/src/freebusy.cpp b/src/freebusy.cpp
--- a/src/freebusy.cpp
+++ b/src/freebusy.cpp
@@ -32,7 +32,7 @@
 */
 #include "freebusy.h"
 #include "visitor.h"
-#include "utils.h"
+#include "utils_p.h"
 
 #include "icalformat.h"
 
diff --git a/src/icalformat_p.cpp b/src/icalformat_p.cpp
--- a/src/icalformat_p.cpp
+++ b/src/icalformat_p.cpp
@@ -45,7 +45,6 @@
 #include "memorycalendar.h"
 #include "todo.h"
 #include "visitor.h"
-#include "utils.h"
 
 #include "kcalcore_debug.h"
 
diff --git a/src/icaltimezones.cpp b/src/icaltimezones.cpp
--- a/src/icaltimezones.cpp
+++ b/src/icaltimezones.cpp
@@ -25,7 +25,6 @@
 #include "recurrence.h"
 #include "recurrencerule.h"
 #include "recurrencehelper_p.h"
-#include "utils.h"
 
 #include "kcalcore_debug.h"
 
diff --git a/src/incidence.cpp b/src/incidence.cpp
--- a/src/incidence.cpp
+++ b/src/incidence.cpp
@@ -34,7 +34,7 @@
 
 #include "incidence.h"
 #include "calformat.h"
-#include "utils.h"
+#include "utils_p.h"
 
 #include <QTextDocument> // for .toHtmlEscaped() and Qt::mightBeRichText()
 #include <QStringList>
diff --git a/src/incidencebase.cpp b/src/incidencebase.cpp
--- a/src/incidencebase.cpp
+++ b/src/incidencebase.cpp
@@ -37,7 +37,7 @@
 #include "incidencebase.h"
 #include "calformat.h"
 #include "visitor.h"
-#include "utils.h"
+#include "utils_p.h"
 
 #include <QTime>
 #include "kcalcore_debug.h"
diff --git a/src/memorycalendar.cpp b/src/memorycalendar.cpp
--- a/src/memorycalendar.cpp
+++ b/src/memorycalendar.cpp
@@ -34,7 +34,6 @@
 
 #include "memorycalendar.h"
 #include "kcalcore_debug.h"
-#include "utils.h"
 #include "calformat.h"
 
 #include <QDate>
diff --git a/src/occurrenceiterator.cpp b/src/occurrenceiterator.cpp
--- a/src/occurrenceiterator.cpp
+++ b/src/occurrenceiterator.cpp
@@ -32,7 +32,6 @@
 #include "occurrenceiterator.h"
 #include "calendar.h"
 #include "calfilter.h"
-#include "utils.h"
 
 #include <QDate>
 
diff --git a/src/period.cpp b/src/period.cpp
--- a/src/period.cpp
+++ b/src/period.cpp
@@ -31,7 +31,7 @@
 */
 
 #include "period.h"
-#include "utils.h"
+#include "utils_p.h"
 
 #include <QHash>
 #include <QTimeZone>
diff --git a/src/recurrence.cpp b/src/recurrence.cpp
--- a/src/recurrence.cpp
+++ b/src/recurrence.cpp
@@ -22,7 +22,7 @@
   Boston, MA 02110-1301, USA.
 */
 #include "recurrence.h"
-#include "utils.h"
+#include "utils_p.h"
 #include "recurrencehelper_p.h"
 
 #include "kcalcore_debug.h"
diff --git a/src/recurrencerule.cpp b/src/recurrencerule.cpp
--- a/src/recurrencerule.cpp
+++ b/src/recurrencerule.cpp
@@ -20,7 +20,7 @@
   Boston, MA 02110-1301, USA.
 */
 #include "recurrencerule.h"
-#include "utils.h"
+#include "utils_p.h"
 #include "kcalcore_debug.h"
 #include "recurrencehelper_p.h"
 
diff --git a/src/sorting.cpp b/src/sorting.cpp
--- a/src/sorting.cpp
+++ b/src/sorting.cpp
@@ -23,7 +23,6 @@
 #include "event.h"
 #include "journal.h"
 #include "todo.h"
-#include "utils.h"
 
 // PENDING(kdab) Review
 // The QString::compare() need to be replace by a DUI string comparisons.
diff --git a/src/todo.cpp b/src/todo.cpp
--- a/src/todo.cpp
+++ b/src/todo.cpp
@@ -34,7 +34,7 @@
 #include "todo.h"
 #include "visitor.h"
 #include "recurrence.h"
-#include "utils.h"
+#include "utils_p.h"
 
 #include "kcalcore_debug.h"
 
diff --git a/src/utils.cpp b/src/utils.cpp
--- a/src/utils.cpp
+++ b/src/utils.cpp
@@ -19,7 +19,7 @@
   Boston, MA 02110-1301, USA.
 */
 
-#include "utils.h"
+#include "utils_p.h"
 
 #include <QTimeZone>
 #include <QDataStream>
diff --git a/src/utils.h b/src/utils_p.h
rename from src/utils.h
rename to src/utils_p.h
--- a/src/utils.h
+++ b/src/utils_p.h
@@ -33,7 +33,7 @@
 /**
  * Helpers to retain backwards compatibility of binary serialization.
  */
-KCALCORE_EXPORT void serializeQDateTimeAsKDateTime(QDataStream &out, const QDateTime &dt);
+void serializeQDateTimeAsKDateTime(QDataStream &out, const QDateTime &dt);
 KCALCORE_EXPORT void deserializeKDateTimeAsQDateTime(QDataStream &in, QDateTime &dt);
 
 void serializeQDateTimeList(QDataStream &out, const QList<QDateTime> &list);
diff --git a/src/vcalformat.cpp b/src/vcalformat.cpp
--- a/src/vcalformat.cpp
+++ b/src/vcalformat.cpp
@@ -39,7 +39,6 @@
 #include "event.h"
 #include "exceptions.h"
 #include "todo.h"
-#include "utils.h"
 
 #include "kcalcore_debug.h"