diff --git a/CMakeLists.txt b/CMakeLists.txt
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -144,7 +144,7 @@
 set(LIBMAILIMPORTER_VERSION_LIB "5.1.41")
 set(MAILCOMMON_LIB_VERSION_LIB "5.1.41")
 set(KDEPIM_APPS_LIB_VERSION_LIB "5.1.42")
-set(MESSAGELIB_LIB_VERSION_LIB "5.1.63")
+set(MESSAGELIB_LIB_VERSION_LIB "5.1.64")
 set(LIBKLEO_LIB_VERSION_LIB "5.1.41")
 set(LIBGRANTLEETHEME_LIB_VERSION_LIB "5.1.41")
 set(PIMCOMMON_LIB_VERSION_LIB "5.1.53")
diff --git a/kmail/kmreadermainwin.cpp b/kmail/kmreadermainwin.cpp
--- a/kmail/kmreadermainwin.cpp
+++ b/kmail/kmreadermainwin.cpp
@@ -132,7 +132,7 @@
 
     mParentCollection = parentCollection;
     mReaderWin->setOverrideEncoding(encoding);
-    mReaderWin->setMessage(msg, MessageViewer::Viewer::Force);
+    mReaderWin->setMessage(msg, MessageViewer::Force);
     KMime::Message::Ptr message = MessageCore::Util::message(msg);
     QString caption;
     if (message) {
diff --git a/kmail/kmreaderwin.h b/kmail/kmreaderwin.h
--- a/kmail/kmreaderwin.h
+++ b/kmail/kmreaderwin.h
@@ -69,7 +69,7 @@
     void setOverrideEncoding(const QString &encoding);
     virtual void setPrinting(bool enable);
 
-    void setMessage(const Akonadi::Item &item, MessageViewer::Viewer::UpdateMode updateMode = MessageViewer::Viewer::Delayed);
+    void setMessage(const Akonadi::Item &item, MessageViewer::UpdateMode updateMode = MessageViewer::Delayed);
 
     void setMessage(const KMime::Message::Ptr &message);
 
diff --git a/kmail/kmreaderwin.cpp b/kmail/kmreaderwin.cpp
--- a/kmail/kmreaderwin.cpp
+++ b/kmail/kmreaderwin.cpp
@@ -622,10 +622,10 @@
 
 void KMReaderWin::clear(bool force)
 {
-    mViewer->clear(force ? Viewer::Force : Viewer::Delayed);
+    mViewer->clear(force ? Force : Delayed);
 }
 
-void KMReaderWin::setMessage(const Akonadi::Item &item, Viewer::UpdateMode updateMode)
+void KMReaderWin::setMessage(const Akonadi::Item &item, UpdateMode updateMode)
 {
     qCDebug(KMAIL_LOG) << Q_FUNC_INFO << parentWidget();
     mViewer->setMessageItem(item, updateMode);
@@ -648,7 +648,7 @@
 
 void KMReaderWin::update(bool force)
 {
-    mViewer->update(force ? Viewer::Force : Viewer::Delayed);
+    mViewer->update(force ? Force : Delayed);
 }
 
 void KMReaderWin::slotUrlClicked(const Akonadi::Item &item, const QUrl &url)
diff --git a/plugins/messageviewer/bodypartformatter/calendar/memorycalendarmemento.h b/plugins/messageviewer/bodypartformatter/calendar/memorycalendarmemento.h
--- a/plugins/messageviewer/bodypartformatter/calendar/memorycalendarmemento.h
+++ b/plugins/messageviewer/bodypartformatter/calendar/memorycalendarmemento.h
@@ -20,9 +20,8 @@
 #ifndef MEMORYCALENDARMEMENTO_H
 #define MEMORYCALENDARMEMENTO_H
 
-#include <messageviewer/bodypart.h>
-
-#include <messageviewer/viewer.h>
+#include <MessageViewer/BodyPart>
+#include <MessageViewer/Enums>
 
 #include <KCalCore/MemoryCalendar>
 #include <QObject>
@@ -45,7 +44,7 @@
 
 Q_SIGNALS:
     // TODO: Factor our update and detach into base class
-    void update(MessageViewer::Viewer::UpdateMode);
+    void update(MessageViewer::UpdateMode);
 
 private Q_SLOTS:
     void slotCalendarLoaded(bool success, const QString &errorMessage);
diff --git a/plugins/messageviewer/bodypartformatter/calendar/memorycalendarmemento.cpp b/plugins/messageviewer/bodypartformatter/calendar/memorycalendarmemento.cpp
--- a/plugins/messageviewer/bodypartformatter/calendar/memorycalendarmemento.cpp
+++ b/plugins/messageviewer/bodypartformatter/calendar/memorycalendarmemento.cpp
@@ -56,7 +56,7 @@
 void MemoryCalendarMemento::finalize()
 {
     mFinished = true;
-    Q_EMIT update(Viewer::Delayed);
+    Q_EMIT update(Delayed);
 }
 
 bool MemoryCalendarMemento::finished() const
@@ -72,6 +72,6 @@
 
 void MemoryCalendarMemento::detach()
 {
-    disconnect(this, SIGNAL(update(MessageViewer::Viewer::UpdateMode)), 0, 0);
+    disconnect(this, &MemoryCalendarMemento::update, 0, 0);
 }
 
diff --git a/plugins/messageviewer/bodypartformatter/calendar/text_calendar.cpp b/plugins/messageviewer/bodypartformatter/calendar/text_calendar.cpp
--- a/plugins/messageviewer/bodypartformatter/calendar/text_calendar.cpp
+++ b/plugins/messageviewer/bodypartformatter/calendar/text_calendar.cpp
@@ -232,8 +232,8 @@
             bodyPart->setBodyPartMemento(memento);
 
             if (asyncResultObserver) {
-                QObject::connect(memento, SIGNAL(update(MessageViewer::Viewer::UpdateMode)),
-                                 asyncResultObserver, SLOT(update(MessageViewer::Viewer::UpdateMode)));
+                QObject::connect(memento, SIGNAL(update(MessageViewer::UpdateMode)),
+                                 asyncResultObserver, SLOT(update(MessageViewer::UpdateMode)));
             }
         }