diff --git a/src/core/Config.cpp b/src/core/Config.cpp
index d89077a1a..9edd67022 100644
--- a/src/core/Config.cpp
+++ b/src/core/Config.cpp
@@ -23,7 +23,7 @@
 #include <QtGui/QApplication>
 #include <QtGui/QDesktopServices>
 
-Config* Config::m_instance(0);
+Config* Config::m_instance(Q_NULLPTR);
 
 QVariant Config::get(const QString& key)
 {
diff --git a/src/core/Config.h b/src/core/Config.h
index 0ebaeeb1b..eab86699e 100644
--- a/src/core/Config.h
+++ b/src/core/Config.h
@@ -21,6 +21,8 @@
 #include <QtCore/QScopedPointer>
 #include <QtCore/QVariant>
 
+#include "core/Global.h"
+
 class QSettings;
 
 class Config : public QObject
diff --git a/src/core/DataPath.cpp b/src/core/DataPath.cpp
index 44709f6de..d12c997ca 100644
--- a/src/core/DataPath.cpp
+++ b/src/core/DataPath.cpp
@@ -22,7 +22,7 @@
 
 #include "config-keepassx.h"
 
-DataPath* DataPath::m_instance(0);
+DataPath* DataPath::m_instance(Q_NULLPTR);
 
 QString DataPath::path(const QString& name)
 {
diff --git a/src/core/DataPath.h b/src/core/DataPath.h
index 71d3bad3f..b0377b54d 100644
--- a/src/core/DataPath.h
+++ b/src/core/DataPath.h
@@ -21,6 +21,8 @@
 #include <QtCore/QString>
 #include <QtGui/QIcon>
 
+#include "core/Global.h"
+
 class DataPath
 {
 public:
diff --git a/src/core/DatabaseIcons.cpp b/src/core/DatabaseIcons.cpp
index b584f4433..44706491b 100644
--- a/src/core/DatabaseIcons.cpp
+++ b/src/core/DatabaseIcons.cpp
@@ -19,7 +19,7 @@
 
 #include "core/DataPath.h"
 
-DatabaseIcons* DatabaseIcons::m_instance(0);
+DatabaseIcons* DatabaseIcons::m_instance(Q_NULLPTR);
 
 QImage DatabaseIcons::icon(int index)
 {
diff --git a/src/core/DatabaseIcons.h b/src/core/DatabaseIcons.h
index 24c81ba95..b7fa3e1a2 100644
--- a/src/core/DatabaseIcons.h
+++ b/src/core/DatabaseIcons.h
@@ -23,6 +23,8 @@
 #include <QtGui/QPixmap>
 #include <QtGui/QPixmapCache>
 
+#include "core/Global.h"
+
 class DatabaseIcons
 {
 public:
diff --git a/src/core/Entry.cpp b/src/core/Entry.cpp
index a3fefde47..7b81785b3 100644
--- a/src/core/Entry.cpp
+++ b/src/core/Entry.cpp
@@ -26,7 +26,7 @@
 Entry::Entry()
 {
     m_updateTimeinfo = true;
-    m_tmpHistoryItem = 0;
+    m_tmpHistoryItem = Q_NULLPTR;
 
     m_data.iconNumber = DefaultIconNumber;
     m_data.autoTypeEnabled = true;
@@ -467,7 +467,7 @@ void Entry::endUpdate()
         delete m_tmpHistoryItem;
     }
 
-    m_tmpHistoryItem = 0;
+    m_tmpHistoryItem = Q_NULLPTR;
 }
 
 void Entry::updateModifiedSinceBegin()
diff --git a/src/core/Entry.h b/src/core/Entry.h
index 1a32a8c89..212da4957 100644
--- a/src/core/Entry.h
+++ b/src/core/Entry.h
@@ -29,6 +29,7 @@
 
 #include "core/EntryAttachments.h"
 #include "core/EntryAttributes.h"
+#include "core/Global.h"
 #include "core/TimeInfo.h"
 #include "core/Uuid.h"
 
diff --git a/src/core/EntryAttachments.h b/src/core/EntryAttachments.h
index 960cc4ea8..db7ce2a4e 100644
--- a/src/core/EntryAttachments.h
+++ b/src/core/EntryAttachments.h
@@ -21,12 +21,14 @@
 #include <QtCore/QMap>
 #include <QtCore/QObject>
 
+#include "core/Global.h"
+
 class EntryAttachments : public QObject
 {
     Q_OBJECT
 
 public:
-    explicit EntryAttachments(QObject* parent = 0);
+    explicit EntryAttachments(QObject* parent = Q_NULLPTR);
     QList<QString> keys() const;
     QByteArray value(const QString& key) const;
     void set(const QString& key, const QByteArray& value);
diff --git a/src/core/EntryAttributes.h b/src/core/EntryAttributes.h
index 108b789c6..67ab7907a 100644
--- a/src/core/EntryAttributes.h
+++ b/src/core/EntryAttributes.h
@@ -23,12 +23,14 @@
 #include <QtCore/QObject>
 #include <QtCore/QStringList>
 
+#include "core/Global.h"
+
 class EntryAttributes : public QObject
 {
     Q_OBJECT
 
 public:
-    explicit EntryAttributes(QObject* parent = 0);
+    explicit EntryAttributes(QObject* parent = Q_NULLPTR);
     QList<QString> keys() const;
     QString value(const QString& key) const;
     bool isProtected(const QString& key) const;
diff --git a/src/core/Group.cpp b/src/core/Group.cpp
index ff203f2cb..161845c91 100644
--- a/src/core/Group.cpp
+++ b/src/core/Group.cpp
@@ -355,7 +355,7 @@ void Group::setParent(Database* db)
 
     cleanupParent();
 
-    m_parent = 0;
+    m_parent = Q_NULLPTR;
     recSetDatabase(db);
 
     QObject::setParent(db);
diff --git a/src/core/Metadata.h b/src/core/Metadata.h
index 7049b6dbd..520143430 100644
--- a/src/core/Metadata.h
+++ b/src/core/Metadata.h
@@ -24,6 +24,7 @@
 #include <QtGui/QColor>
 #include <QtGui/QImage>
 
+#include "core/Global.h"
 #include "core/Uuid.h"
 
 class Database;
@@ -34,7 +35,7 @@ class Metadata : public QObject
     Q_OBJECT
 
 public:
-    explicit Metadata(QObject* parent = 0);
+    explicit Metadata(QObject* parent = Q_NULLPTR);
 
     QString generator() const;
     QString name() const;
diff --git a/src/crypto/Crypto.h b/src/crypto/Crypto.h
index d1b2004b9..63f117771 100644
--- a/src/crypto/Crypto.h
+++ b/src/crypto/Crypto.h
@@ -18,6 +18,8 @@
 #ifndef KEEPASSX_CRYPTO_H
 #define KEEPASSX_CRYPTO_H
 
+#include "core/Global.h"
+
 class Crypto
 {
 public:
diff --git a/src/crypto/SymmetricCipherGcrypt.cpp b/src/crypto/SymmetricCipherGcrypt.cpp
index 94a24429e..6ea9d7467 100644
--- a/src/crypto/SymmetricCipherGcrypt.cpp
+++ b/src/crypto/SymmetricCipherGcrypt.cpp
@@ -71,7 +71,7 @@ void SymmetricCipherGcrypt::init()
     Q_ASSERT(error == 0); // TODO: real error checking
 
     size_t blockSizeT;
-    error = gcry_cipher_algo_info(m_algo, GCRYCTL_GET_BLKLEN, 0, &blockSizeT);
+    error = gcry_cipher_algo_info(m_algo, GCRYCTL_GET_BLKLEN, Q_NULLPTR, &blockSizeT);
     Q_ASSERT(error == 0);
     m_blockSize = blockSizeT;
 }
@@ -118,10 +118,10 @@ void SymmetricCipherGcrypt::processInPlace(QByteArray& data)
     gcry_error_t error;
 
     if (m_direction == SymmetricCipher::Decrypt) {
-        error = gcry_cipher_decrypt(m_ctx, data.data(), data.size(), 0, 0);
+        error = gcry_cipher_decrypt(m_ctx, data.data(), data.size(), Q_NULLPTR, 0);
     }
     else {
-        error = gcry_cipher_encrypt(m_ctx, data.data(), data.size(), 0, 0);
+        error = gcry_cipher_encrypt(m_ctx, data.data(), data.size(), Q_NULLPTR, 0);
     }
 
     Q_ASSERT(error == 0);
@@ -135,13 +135,13 @@ void SymmetricCipherGcrypt::processInPlace(QByteArray& data, quint64 rounds)
 
     if (m_direction == SymmetricCipher::Decrypt) {
         for (quint64 i = 0; i != rounds; ++i) {
-            error = gcry_cipher_decrypt(m_ctx, data.data(), data.size(), 0, 0);
+            error = gcry_cipher_decrypt(m_ctx, data.data(), data.size(), Q_NULLPTR, 0);
             Q_ASSERT(error == 0);
         }
     }
     else {
         for (quint64 i = 0; i != rounds; ++i) {
-            error = gcry_cipher_encrypt(m_ctx, data.data(), data.size(), 0, 0);
+            error = gcry_cipher_encrypt(m_ctx, data.data(), data.size(), Q_NULLPTR, 0);
             Q_ASSERT(error == 0);
         }
     }
diff --git a/src/format/KeePass2XmlReader.cpp b/src/format/KeePass2XmlReader.cpp
index 564f5394b..b0e540542 100644
--- a/src/format/KeePass2XmlReader.cpp
+++ b/src/format/KeePass2XmlReader.cpp
@@ -29,9 +29,9 @@
 #include "streams/QtIOCompressor"
 
 KeePass2XmlReader::KeePass2XmlReader()
-    : m_randomStream(0)
-    , m_db(0)
-    , m_meta(0)
+    : m_randomStream(Q_NULLPTR)
+    , m_db(Q_NULLPTR)
+    , m_meta(Q_NULLPTR)
 {
 }
 
@@ -400,7 +400,7 @@ Group* KeePass2XmlReader::parseGroup()
 {
     Q_ASSERT(m_xml.isStartElement() && m_xml.name() == "Group");
 
-    Group* group = 0;
+    Group* group = Q_NULLPTR;
     while (!m_xml.error() && m_xml.readNextStartElement()) {
         if (m_xml.name() == "UUID") {
             Uuid uuid = readUuid();
diff --git a/src/format/KeePass2XmlReader.h b/src/format/KeePass2XmlReader.h
index f75c6e868..556bcdba2 100644
--- a/src/format/KeePass2XmlReader.h
+++ b/src/format/KeePass2XmlReader.h
@@ -25,6 +25,7 @@
 #include <QtCore/QXmlStreamReader>
 #include <QtGui/QColor>
 
+#include "core/Global.h"
 #include "core/TimeInfo.h"
 #include "core/Uuid.h"
 
@@ -41,7 +42,7 @@ class KeePass2XmlReader
 public:
     KeePass2XmlReader();
     Database* readDatabase(QIODevice* device);
-    void readDatabase(QIODevice* device, Database* db, KeePass2RandomStream* randomStream = 0);
+    void readDatabase(QIODevice* device, Database* db, KeePass2RandomStream* randomStream = Q_NULLPTR);
     Database* readDatabase(const QString& filename);
     bool hasError();
     QString errorString();
diff --git a/src/format/KeePass2XmlWriter.cpp b/src/format/KeePass2XmlWriter.cpp
index c64ba796a..189887d68 100644
--- a/src/format/KeePass2XmlWriter.cpp
+++ b/src/format/KeePass2XmlWriter.cpp
@@ -25,9 +25,9 @@
 #include "streams/QtIOCompressor"
 
 KeePass2XmlWriter::KeePass2XmlWriter()
-    : m_db(0)
-    , m_meta(0)
-    , m_randomStream(0)
+    : m_db(Q_NULLPTR)
+    , m_meta(Q_NULLPTR)
+    , m_randomStream(Q_NULLPTR)
 {
     m_xml.setAutoFormatting(true);
     m_xml.setAutoFormattingIndent(-1); // 1 tab
diff --git a/src/format/KeePass2XmlWriter.h b/src/format/KeePass2XmlWriter.h
index 289ac4744..35666f0b0 100644
--- a/src/format/KeePass2XmlWriter.h
+++ b/src/format/KeePass2XmlWriter.h
@@ -36,8 +36,8 @@ class KeePass2XmlWriter
 {
 public:
     KeePass2XmlWriter();
-    void writeDatabase(QIODevice* device, Database* db, KeePass2RandomStream* randomStream = 0);
-    void writeDatabase(const QString& filename, Database* db, KeePass2RandomStream* randomStream = 0);
+    void writeDatabase(QIODevice* device, Database* db, KeePass2RandomStream* randomStream = Q_NULLPTR);
+    void writeDatabase(const QString& filename, Database* db, KeePass2RandomStream* randomStream = Q_NULLPTR);
     bool error();
     QString errorString();
 
diff --git a/src/gui/AboutDialog.h b/src/gui/AboutDialog.h
index 369a40208..051e831d9 100644
--- a/src/gui/AboutDialog.h
+++ b/src/gui/AboutDialog.h
@@ -21,6 +21,8 @@
 #include <QtCore/QScopedPointer>
 #include <QtGui/QDialog>
 
+#include "core/Global.h"
+
 namespace Ui {
     class AboutDialog;
 }
@@ -30,7 +32,7 @@ class AboutDialog : public QDialog
     Q_OBJECT
 
 public:
-    explicit AboutDialog(QWidget* parent = 0);
+    explicit AboutDialog(QWidget* parent = Q_NULLPTR);
     ~AboutDialog();
 
 private:
diff --git a/src/gui/ChangeMasterKeyWidget.h b/src/gui/ChangeMasterKeyWidget.h
index 4342a933f..4995d0316 100644
--- a/src/gui/ChangeMasterKeyWidget.h
+++ b/src/gui/ChangeMasterKeyWidget.h
@@ -33,7 +33,7 @@ class ChangeMasterKeyWidget : public DialogyWidget
     Q_OBJECT
 
 public:
-    explicit ChangeMasterKeyWidget(QWidget* parent = 0);
+    explicit ChangeMasterKeyWidget(QWidget* parent = Q_NULLPTR);
     ~ChangeMasterKeyWidget();
     void clearForms();
     CompositeKey newMasterKey();
diff --git a/src/gui/Clipboard.cpp b/src/gui/Clipboard.cpp
index 90eeb2d85..a1e95860e 100644
--- a/src/gui/Clipboard.cpp
+++ b/src/gui/Clipboard.cpp
@@ -28,7 +28,7 @@
 
 #include "core/Config.h"
 
-Clipboard* Clipboard::m_instance(0);
+Clipboard* Clipboard::m_instance(Q_NULLPTR);
 
 Clipboard::Clipboard(QObject* parent)
     : QObject(parent)
diff --git a/src/gui/Clipboard.h b/src/gui/Clipboard.h
index f8780c7a0..51ec73dc1 100644
--- a/src/gui/Clipboard.h
+++ b/src/gui/Clipboard.h
@@ -20,6 +20,8 @@
 
 #include <QtCore/QObject>
 
+#include "core/Global.h"
+
 class QTimer;
 
 class Clipboard : public QObject
@@ -36,7 +38,7 @@ private Q_SLOTS:
     void clearClipboard();
 
 private:
-    explicit Clipboard(QObject* parent = 0);
+    explicit Clipboard(QObject* parent = Q_NULLPTR);
 
     static Clipboard* m_instance;
 
diff --git a/src/gui/DatabaseOpenWidget.cpp b/src/gui/DatabaseOpenWidget.cpp
index 61f601b5d..9f74f1e96 100644
--- a/src/gui/DatabaseOpenWidget.cpp
+++ b/src/gui/DatabaseOpenWidget.cpp
@@ -30,8 +30,8 @@
 DatabaseOpenWidget::DatabaseOpenWidget(QWidget* parent)
     : DialogyWidget(parent)
     , m_ui(new Ui::DatabaseOpenWidget())
-    , m_db(0)
-    , m_file(0)
+    , m_db(Q_NULLPTR)
+    , m_file(Q_NULLPTR)
 {
     m_ui->setupUi(this);
 
diff --git a/src/gui/DatabaseOpenWidget.h b/src/gui/DatabaseOpenWidget.h
index 5a6ea22f1..955e5ec5c 100644
--- a/src/gui/DatabaseOpenWidget.h
+++ b/src/gui/DatabaseOpenWidget.h
@@ -34,7 +34,7 @@ class DatabaseOpenWidget : public DialogyWidget
     Q_OBJECT
 
 public:
-    DatabaseOpenWidget(QWidget* parent = 0);
+    DatabaseOpenWidget(QWidget* parent = Q_NULLPTR);
     ~DatabaseOpenWidget();
     void load(QFile* file, const QString& filename);
     void enterKey(const QString& pw, const QString& keyFile);
diff --git a/src/gui/DatabaseSettingsWidget.cpp b/src/gui/DatabaseSettingsWidget.cpp
index 33a700bc6..f7071f423 100644
--- a/src/gui/DatabaseSettingsWidget.cpp
+++ b/src/gui/DatabaseSettingsWidget.cpp
@@ -26,7 +26,7 @@
 DatabaseSettingsWidget::DatabaseSettingsWidget(QWidget* parent)
     : DialogyWidget(parent)
     , m_ui(new Ui::DatabaseSettingsWidget())
-    , m_db(0)
+    , m_db(Q_NULLPTR)
 {
     m_ui->setupUi(this);
 
diff --git a/src/gui/DatabaseSettingsWidget.h b/src/gui/DatabaseSettingsWidget.h
index bd83abe49..1b6e36ab7 100644
--- a/src/gui/DatabaseSettingsWidget.h
+++ b/src/gui/DatabaseSettingsWidget.h
@@ -33,7 +33,7 @@ class DatabaseSettingsWidget : public DialogyWidget
     Q_OBJECT
 
 public:
-    explicit DatabaseSettingsWidget(QWidget* parent = 0);
+    explicit DatabaseSettingsWidget(QWidget* parent = Q_NULLPTR);
     ~DatabaseSettingsWidget();
 
     void load(Database* db);
diff --git a/src/gui/DatabaseTabWidget.cpp b/src/gui/DatabaseTabWidget.cpp
index c8b54e067..9869cbab7 100644
--- a/src/gui/DatabaseTabWidget.cpp
+++ b/src/gui/DatabaseTabWidget.cpp
@@ -32,8 +32,8 @@
 #include "gui/group/GroupView.h"
 
 DatabaseManagerStruct::DatabaseManagerStruct()
-    : file(0)
-    , dbWidget(0)
+    : file(Q_NULLPTR)
+    , dbWidget(Q_NULLPTR)
     , modified(false)
     , readOnly(false)
 {
diff --git a/src/gui/DatabaseTabWidget.h b/src/gui/DatabaseTabWidget.h
index da0d65a28..af7ab315b 100644
--- a/src/gui/DatabaseTabWidget.h
+++ b/src/gui/DatabaseTabWidget.h
@@ -99,7 +99,7 @@ private:
     Database* databaseFromDatabaseWidget(DatabaseWidget* dbWidget);
     void insertDatabase(Database* db, const DatabaseManagerStruct& dbStruct);
     void updateLastDatabases(const QString& filename);
-    void connectDatabase(Database* newDb, Database* oldDb = 0);
+    void connectDatabase(Database* newDb, Database* oldDb = Q_NULLPTR);
 
     QWidget* const m_window;
     KeePass2Writer m_writer;
diff --git a/src/gui/DatabaseWidget.cpp b/src/gui/DatabaseWidget.cpp
index 21a061871..c4c01b3aa 100644
--- a/src/gui/DatabaseWidget.cpp
+++ b/src/gui/DatabaseWidget.cpp
@@ -45,9 +45,9 @@ DatabaseWidget::DatabaseWidget(Database* db, QWidget* parent)
     , m_db(db)
     , m_searchUi(new Ui::SearchWidget())
     , m_searchWidget(new QWidget())
-    , m_newGroup(0)
-    , m_newEntry(0)
-    , m_newParent(0)
+    , m_newGroup(Q_NULLPTR)
+    , m_newEntry(Q_NULLPTR)
+    , m_newParent(Q_NULLPTR)
     , m_menuGroup(new QMenu(this))
     , m_menuEntry(new QMenu(this))
 {
@@ -394,8 +394,8 @@ void DatabaseWidget::switchToView(bool accepted)
             delete m_newGroup;
         }
 
-        m_newGroup = 0;
-        m_newParent = 0;
+        m_newGroup = Q_NULLPTR;
+        m_newParent = Q_NULLPTR;
     }
     else if (m_newEntry) {
         if (accepted) {
@@ -407,8 +407,8 @@ void DatabaseWidget::switchToView(bool accepted)
             delete m_newEntry;
         }
 
-        m_newEntry = 0;
-        m_newParent = 0;
+        m_newEntry = Q_NULLPTR;
+        m_newParent = Q_NULLPTR;
     }
 
     setCurrentIndex(0);
@@ -475,9 +475,9 @@ void DatabaseWidget::openDatabase(bool accepted)
         // We won't need those anymore and KeePass1OpenWidget closes
         // the file in its dtor.
         delete m_databaseOpenWidget;
-        m_databaseOpenWidget = 0;
+        m_databaseOpenWidget = Q_NULLPTR;
         delete m_keepass1OpenWidget;
-        m_keepass1OpenWidget = 0;
+        m_keepass1OpenWidget = Q_NULLPTR;
     }
     else {
         if (m_databaseOpenWidget->database()) {
@@ -641,7 +641,7 @@ bool DatabaseWidget::canDeleteCurrentGoup()
 void DatabaseWidget::clearLastGroup(Group* group)
 {
     if (group) {
-        m_lastGroup = 0;
+        m_lastGroup = Q_NULLPTR;
         m_searchWidget->hide();
     }
 }
diff --git a/src/gui/DatabaseWidget.h b/src/gui/DatabaseWidget.h
index b83b79a57..b9e93abdd 100644
--- a/src/gui/DatabaseWidget.h
+++ b/src/gui/DatabaseWidget.h
@@ -21,6 +21,8 @@
 #include <QtCore/QScopedPointer>
 #include <QtGui/QStackedWidget>
 
+#include "core/Global.h"
+
 class ChangeMasterKeyWidget;
 class DatabaseOpenWidget;
 class DatabaseSettingsWidget;
@@ -63,7 +65,7 @@ public:
         EntryCopyPassword
     };
 
-    explicit DatabaseWidget(Database* db, QWidget* parent = 0);
+    explicit DatabaseWidget(Database* db, QWidget* parent = Q_NULLPTR);
     ~DatabaseWidget();
     GroupView* groupView();
     EntryView* entryView();
diff --git a/src/gui/DialogyWidget.h b/src/gui/DialogyWidget.h
index 2d12f8285..68ca6a088 100644
--- a/src/gui/DialogyWidget.h
+++ b/src/gui/DialogyWidget.h
@@ -21,12 +21,14 @@
 #include <QtGui/QDialogButtonBox>
 #include <QtGui/QWidget>
 
+#include "core/Global.h"
+
 class DialogyWidget : public QWidget
 {
     Q_OBJECT
 
 public:
-    explicit DialogyWidget(QWidget* parent = 0);
+    explicit DialogyWidget(QWidget* parent = Q_NULLPTR);
 
 protected:
     virtual void keyPressEvent(QKeyEvent* e);
diff --git a/src/gui/DragTabBar.h b/src/gui/DragTabBar.h
index 1bb3238b2..9b265a505 100644
--- a/src/gui/DragTabBar.h
+++ b/src/gui/DragTabBar.h
@@ -20,12 +20,14 @@
 
 #include <QtGui/QTabBar>
 
+#include "core/Global.h"
+
 class DragTabBar : public QTabBar
 {
     Q_OBJECT
 
 public:
-    explicit DragTabBar(QWidget* parent = 0);
+    explicit DragTabBar(QWidget* parent = Q_NULLPTR);
 
 protected:
     void dragEnterEvent(QDragEnterEvent* event);
diff --git a/src/gui/EditWidget.h b/src/gui/EditWidget.h
index 9bb8a03ea..ff44cef22 100644
--- a/src/gui/EditWidget.h
+++ b/src/gui/EditWidget.h
@@ -33,7 +33,7 @@ class EditWidget : public DialogyWidget
     Q_OBJECT
 
 public:
-    explicit EditWidget(QWidget* parent = 0);
+    explicit EditWidget(QWidget* parent = Q_NULLPTR);
     ~EditWidget();
 
     void add(const QString& labelText, QWidget* widget);
diff --git a/src/gui/EditWidgetIcons.cpp b/src/gui/EditWidgetIcons.cpp
index f9b52ca2f..a29c644a3 100644
--- a/src/gui/EditWidgetIcons.cpp
+++ b/src/gui/EditWidgetIcons.cpp
@@ -85,7 +85,7 @@ IconStruct EditWidgetIcons::save()
         }
     }
 
-    m_database = 0;
+    m_database = Q_NULLPTR;
     m_currentUuid = Uuid();
     return iconStruct;
 }
diff --git a/src/gui/EditWidgetIcons.h b/src/gui/EditWidgetIcons.h
index d529f85d0..859b4f1f1 100644
--- a/src/gui/EditWidgetIcons.h
+++ b/src/gui/EditWidgetIcons.h
@@ -20,6 +20,7 @@
 
 #include <QtGui/QWidget>
 
+#include "core/Global.h"
 #include "core/Uuid.h"
 
 class Database;
@@ -43,7 +44,7 @@ class EditWidgetIcons : public QWidget
     Q_OBJECT
 
 public:
-    explicit EditWidgetIcons(QWidget* parent = 0);
+    explicit EditWidgetIcons(QWidget* parent = Q_NULLPTR);
     ~EditWidgetIcons();
 
     IconStruct save();
diff --git a/src/gui/FileDialog.cpp b/src/gui/FileDialog.cpp
index 620a4ef4c..1d24fc9f0 100644
--- a/src/gui/FileDialog.cpp
+++ b/src/gui/FileDialog.cpp
@@ -19,7 +19,7 @@
 
 #include "core/Config.h"
 
-FileDialog* FileDialog::m_instance(0);
+FileDialog* FileDialog::m_instance(Q_NULLPTR);
 
 QString FileDialog::getOpenFileName(QWidget* parent, const QString& caption, QString dir,
                                     const QString& filter, QString* selectedFilter,
diff --git a/src/gui/FileDialog.h b/src/gui/FileDialog.h
index 0b6fdae40..99db198bf 100644
--- a/src/gui/FileDialog.h
+++ b/src/gui/FileDialog.h
@@ -20,15 +20,17 @@
 
 #include <QtGui/QFileDialog>
 
+#include "core/Global.h"
+
 class FileDialog
 {
 public:
-    QString getOpenFileName(QWidget* parent = 0, const QString& caption = QString(),
+    QString getOpenFileName(QWidget* parent = Q_NULLPTR, const QString& caption = QString(),
                             QString dir = QString(), const QString& filter = QString(),
-                            QString* selectedFilter = 0, QFileDialog::Options options = 0);
-    QString getSaveFileName(QWidget* parent = 0, const QString& caption = QString(),
+                            QString* selectedFilter = Q_NULLPTR, QFileDialog::Options options = Q_NULLPTR);
+    QString getSaveFileName(QWidget* parent = Q_NULLPTR, const QString& caption = QString(),
                             QString dir = QString(), const QString& filter = QString(),
-                            QString* selectedFilter = 0, QFileDialog::Options options = 0);
+                            QString* selectedFilter = Q_NULLPTR, QFileDialog::Options options = Q_NULLPTR);
 
     /**
      * Sets the result of the next get* method call.
diff --git a/src/gui/IconModels.h b/src/gui/IconModels.h
index 163569c66..bc3b3ffd0 100644
--- a/src/gui/IconModels.h
+++ b/src/gui/IconModels.h
@@ -21,6 +21,7 @@
 #include <QtCore/QAbstractListModel>
 #include <QtGui/QImage>
 
+#include "core/Global.h"
 #include "core/Uuid.h"
 
 class DefaultIconModel : public QAbstractListModel
@@ -28,7 +29,7 @@ class DefaultIconModel : public QAbstractListModel
     Q_OBJECT
 
 public:
-    explicit DefaultIconModel(QObject* parent = 0);
+    explicit DefaultIconModel(QObject* parent = Q_NULLPTR);
 
     int rowCount(const QModelIndex& parent = QModelIndex()) const;
     QVariant data(const QModelIndex& index, int role = Qt::DisplayRole) const;
@@ -39,7 +40,7 @@ class CustomIconModel : public QAbstractListModel
     Q_OBJECT
 
 public:
-    explicit CustomIconModel(QObject* parent = 0);
+    explicit CustomIconModel(QObject* parent = Q_NULLPTR);
 
     virtual int rowCount(const QModelIndex& parent = QModelIndex()) const;
     virtual QVariant data(const QModelIndex& index, int role = Qt::DisplayRole) const;
diff --git a/src/gui/KeePass1OpenWidget.h b/src/gui/KeePass1OpenWidget.h
index fc8a849e1..449d2c6f8 100644
--- a/src/gui/KeePass1OpenWidget.h
+++ b/src/gui/KeePass1OpenWidget.h
@@ -25,7 +25,7 @@ class KeePass1OpenWidget : public DatabaseOpenWidget
     Q_OBJECT
 
 public:
-    explicit KeePass1OpenWidget(QWidget* parent = 0);
+    explicit KeePass1OpenWidget(QWidget* parent = Q_NULLPTR);
     ~KeePass1OpenWidget();
 
 protected:
diff --git a/src/gui/LineEdit.h b/src/gui/LineEdit.h
index 802180f12..de7e74210 100644
--- a/src/gui/LineEdit.h
+++ b/src/gui/LineEdit.h
@@ -22,6 +22,8 @@
 
 #include <QtGui/QLineEdit>
 
+#include "core/Global.h"
+
 class QToolButton;
 
 class LineEdit : public QLineEdit
@@ -29,7 +31,7 @@ class LineEdit : public QLineEdit
     Q_OBJECT
 
 public:
-    explicit LineEdit(QWidget* parent = 0);
+    explicit LineEdit(QWidget* parent = Q_NULLPTR);
 
 protected:
     void resizeEvent(QResizeEvent* event);
diff --git a/src/gui/SettingsWidget.h b/src/gui/SettingsWidget.h
index affdd0a90..61a2669d8 100644
--- a/src/gui/SettingsWidget.h
+++ b/src/gui/SettingsWidget.h
@@ -30,7 +30,7 @@ class SettingsWidget : public EditWidget
     Q_OBJECT
 
 public:
-    explicit SettingsWidget(QWidget* parent = 0);
+    explicit SettingsWidget(QWidget* parent = Q_NULLPTR);
     ~SettingsWidget();
     void loadSettings();
 
diff --git a/src/gui/WelcomeWidget.h b/src/gui/WelcomeWidget.h
index 09bbc8fbc..43497ebf7 100644
--- a/src/gui/WelcomeWidget.h
+++ b/src/gui/WelcomeWidget.h
@@ -20,6 +20,8 @@
 
 #include <QtGui/QWidget>
 
+#include "core/Global.h"
+
 namespace Ui {
     class WelcomeWidget;
 }
@@ -29,7 +31,7 @@ class WelcomeWidget : public QWidget
     Q_OBJECT
 
 public:
-    explicit WelcomeWidget(QWidget* parent = 0);
+    explicit WelcomeWidget(QWidget* parent = Q_NULLPTR);
     ~WelcomeWidget();
 
 private:
diff --git a/src/gui/entry/EditEntryWidget.cpp b/src/gui/entry/EditEntryWidget.cpp
index fee6ecba0..f8866566b 100644
--- a/src/gui/entry/EditEntryWidget.cpp
+++ b/src/gui/entry/EditEntryWidget.cpp
@@ -40,7 +40,7 @@
 
 EditEntryWidget::EditEntryWidget(QWidget* parent)
     : EditWidget(parent)
-    , m_entry(0)
+    , m_entry(Q_NULLPTR)
     , m_mainUi(new Ui::EditEntryWidgetMain())
     , m_notesUi(new Ui::EditEntryWidgetNotes())
     , m_advancedUi(new Ui::EditEntryWidgetAdvanced())
@@ -267,8 +267,8 @@ void EditEntryWidget::setForms(const Entry* entry, bool restore)
 void EditEntryWidget::saveEntry()
 {
     if (m_history) {
-        m_entry = 0;
-        m_database = 0;
+        m_entry = Q_NULLPTR;
+        m_database = Q_NULLPTR;
         m_entryAttributes->clear();
         m_entryAttachments->clear();
         Q_EMIT editFinished(false);
@@ -325,8 +325,8 @@ void EditEntryWidget::saveEntry()
     }
 
 
-    m_entry = 0;
-    m_database = 0;
+    m_entry = Q_NULLPTR;
+    m_database = Q_NULLPTR;
     m_entryAttributes->clear();
     m_entryAttachments->clear();
     m_historyModel->clear();
@@ -337,8 +337,8 @@ void EditEntryWidget::saveEntry()
 void EditEntryWidget::cancel()
 {
     if (m_history) {
-        m_entry = 0;
-        m_database = 0;
+        m_entry = Q_NULLPTR;
+        m_database = Q_NULLPTR;
         m_entryAttributes->clear();
         m_entryAttachments->clear();
         Q_EMIT editFinished(false);
diff --git a/src/gui/entry/EditEntryWidget.h b/src/gui/entry/EditEntryWidget.h
index 81074a941..3b9687fb2 100644
--- a/src/gui/entry/EditEntryWidget.h
+++ b/src/gui/entry/EditEntryWidget.h
@@ -47,7 +47,7 @@ class EditEntryWidget : public EditWidget
     Q_OBJECT
 
 public:
-    explicit EditEntryWidget(QWidget* parent = 0);
+    explicit EditEntryWidget(QWidget* parent = Q_NULLPTR);
     ~EditEntryWidget();
 
     void loadEntry(Entry* entry, bool create, bool history, const QString& groupName,
diff --git a/src/gui/entry/EntryAttachmentsModel.cpp b/src/gui/entry/EntryAttachmentsModel.cpp
index d627d2874..e072d177a 100644
--- a/src/gui/entry/EntryAttachmentsModel.cpp
+++ b/src/gui/entry/EntryAttachmentsModel.cpp
@@ -22,7 +22,7 @@
 
 EntryAttachmentsModel::EntryAttachmentsModel(QObject* parent)
     : QAbstractListModel(parent)
-    , m_entryAttachments(0)
+    , m_entryAttachments(Q_NULLPTR)
 {
 }
 
diff --git a/src/gui/entry/EntryAttachmentsModel.h b/src/gui/entry/EntryAttachmentsModel.h
index 5501bd87a..19900b27b 100644
--- a/src/gui/entry/EntryAttachmentsModel.h
+++ b/src/gui/entry/EntryAttachmentsModel.h
@@ -20,6 +20,8 @@
 
 #include <QtCore/QAbstractListModel>
 
+#include "core/Global.h"
+
 class EntryAttachments;
 
 class EntryAttachmentsModel : public QAbstractListModel
@@ -27,7 +29,7 @@ class EntryAttachmentsModel : public QAbstractListModel
     Q_OBJECT
 
 public:
-    explicit EntryAttachmentsModel(QObject* parent = 0);
+    explicit EntryAttachmentsModel(QObject* parent = Q_NULLPTR);
     void setEntryAttachments(EntryAttachments* entry);
     int rowCount(const QModelIndex& parent = QModelIndex()) const;
     int columnCount(const QModelIndex& parent = QModelIndex()) const;
diff --git a/src/gui/entry/EntryAttributesModel.cpp b/src/gui/entry/EntryAttributesModel.cpp
index fa7c9a357..f73a2d2e2 100644
--- a/src/gui/entry/EntryAttributesModel.cpp
+++ b/src/gui/entry/EntryAttributesModel.cpp
@@ -22,7 +22,7 @@
 
 EntryAttributesModel::EntryAttributesModel(QObject* parent)
     : QAbstractListModel(parent)
-    , m_entryAttributes(0)
+    , m_entryAttributes(Q_NULLPTR)
     , m_nextRenameDataChange(false)
 {
 }
diff --git a/src/gui/entry/EntryAttributesModel.h b/src/gui/entry/EntryAttributesModel.h
index c8a89a3f6..286f38f73 100644
--- a/src/gui/entry/EntryAttributesModel.h
+++ b/src/gui/entry/EntryAttributesModel.h
@@ -20,6 +20,8 @@
 
 #include <QtCore/QAbstractListModel>
 
+#include "core/Global.h"
+
 class EntryAttributes;
 
 class EntryAttributesModel : public QAbstractListModel
@@ -27,7 +29,7 @@ class EntryAttributesModel : public QAbstractListModel
     Q_OBJECT
 
 public:
-    explicit EntryAttributesModel(QObject* parent = 0);
+    explicit EntryAttributesModel(QObject* parent = Q_NULLPTR);
     void setEntryAttributes(EntryAttributes* entryAttributes);
     int rowCount(const QModelIndex& parent = QModelIndex()) const;
     int columnCount(const QModelIndex& parent = QModelIndex()) const;
diff --git a/src/gui/entry/EntryHistoryModel.h b/src/gui/entry/EntryHistoryModel.h
index db7d08c37..a2150c434 100644
--- a/src/gui/entry/EntryHistoryModel.h
+++ b/src/gui/entry/EntryHistoryModel.h
@@ -20,6 +20,8 @@
 
 #include <QtCore/QAbstractTableModel>
 
+#include "core/Global.h"
+
 class Entry;
 
 class EntryHistoryModel : public QAbstractTableModel
@@ -27,7 +29,7 @@ class EntryHistoryModel : public QAbstractTableModel
     Q_OBJECT
 
 public:
-    explicit EntryHistoryModel(QObject* parent = 0);
+    explicit EntryHistoryModel(QObject* parent = Q_NULLPTR);
 
     Entry* entryFromIndex(const QModelIndex& index) const;
     int columnCount(const QModelIndex& parent = QModelIndex()) const;
diff --git a/src/gui/entry/EntryModel.cpp b/src/gui/entry/EntryModel.cpp
index 90e4f450b..a2327fe7b 100644
--- a/src/gui/entry/EntryModel.cpp
+++ b/src/gui/entry/EntryModel.cpp
@@ -26,7 +26,7 @@
 
 EntryModel::EntryModel(QObject* parent)
     : QAbstractTableModel(parent)
-    , m_group(0)
+    , m_group(Q_NULLPTR)
 {
     setSupportedDragActions(Qt::MoveAction);
 }
@@ -69,7 +69,7 @@ void EntryModel::setEntries(const QList<Entry*>& entries)
 
     severConnections();
 
-    m_group = 0;
+    m_group = Q_NULLPTR;
     m_allGroups.clear();
     m_entries = entries;
 
@@ -257,11 +257,11 @@ void EntryModel::entryDataChanged(Entry* entry)
 void EntryModel::severConnections()
 {
     if (m_group) {
-        disconnect(m_group, 0, this, 0);
+        disconnect(m_group, Q_NULLPTR, this, Q_NULLPTR);
     }
 
     Q_FOREACH (const Group* group, m_allGroups) {
-        disconnect(group, 0, this, 0);
+        disconnect(group, Q_NULLPTR, this, Q_NULLPTR);
     }
 }
 
diff --git a/src/gui/entry/EntryModel.h b/src/gui/entry/EntryModel.h
index 41d10b138..2f4aa4213 100644
--- a/src/gui/entry/EntryModel.h
+++ b/src/gui/entry/EntryModel.h
@@ -20,6 +20,8 @@
 
 #include <QtCore/QAbstractTableModel>
 
+#include "core/Global.h"
+
 class Entry;
 class Group;
 
@@ -28,7 +30,7 @@ class EntryModel : public QAbstractTableModel
     Q_OBJECT
 
 public:
-    explicit EntryModel(QObject* parent = 0);
+    explicit EntryModel(QObject* parent = Q_NULLPTR);
     Entry* entryFromIndex(const QModelIndex& index) const;
     QModelIndex indexFromEntry(Entry* entry) const;
 
diff --git a/src/gui/entry/EntryView.h b/src/gui/entry/EntryView.h
index 02b66cb1a..a98b6f97e 100644
--- a/src/gui/entry/EntryView.h
+++ b/src/gui/entry/EntryView.h
@@ -20,6 +20,8 @@
 
 #include <QtGui/QTreeView>
 
+#include "core/Global.h"
+
 class Entry;
 class EntryModel;
 class Group;
@@ -30,7 +32,7 @@ class EntryView : public QTreeView
     Q_OBJECT
 
 public:
-    explicit EntryView(QWidget* parent = 0);
+    explicit EntryView(QWidget* parent = Q_NULLPTR);
     void setModel(QAbstractItemModel* model);
     Entry* currentEntry();
     bool isSingleEntrySelected();
diff --git a/src/gui/group/EditGroupWidget.cpp b/src/gui/group/EditGroupWidget.cpp
index f5ee44b76..7a89037e8 100644
--- a/src/gui/group/EditGroupWidget.cpp
+++ b/src/gui/group/EditGroupWidget.cpp
@@ -30,7 +30,7 @@ EditGroupWidget::EditGroupWidget(QWidget* parent)
     , m_editGroupWidgetMain(new QWidget())
     , m_editGroupWidgetIcons(new EditWidgetIcons())
     , m_editGroupWidgetAdvanced(new QWidget())
-    , m_group(0)
+    , m_group(Q_NULLPTR)
 {
     m_mainUi->setupUi(m_editGroupWidgetMain);
     m_advancedUi->setupUi(m_editGroupWidgetAdvanced);
@@ -133,8 +133,8 @@ void EditGroupWidget::save()
         m_group->setIcon(iconStruct.uuid);
     }
 
-    m_group = 0;
-    m_database = 0;
+    m_group = Q_NULLPTR;
+    m_database = Q_NULLPTR;
     Q_EMIT editFinished(true);
 }
 
@@ -145,7 +145,7 @@ void EditGroupWidget::cancel()
         m_group->setIcon(Entry::DefaultIconNumber);
     }
 
-    m_group = 0;
-    m_database = 0;
+    m_group = Q_NULLPTR;
+    m_database = Q_NULLPTR;
     Q_EMIT editFinished(false);
 }
diff --git a/src/gui/group/EditGroupWidget.h b/src/gui/group/EditGroupWidget.h
index 8a8af6150..371fae484 100644
--- a/src/gui/group/EditGroupWidget.h
+++ b/src/gui/group/EditGroupWidget.h
@@ -36,7 +36,7 @@ class EditGroupWidget : public EditWidget
     Q_OBJECT
 
 public:
-    explicit EditGroupWidget(QWidget* parent = 0);
+    explicit EditGroupWidget(QWidget* parent = Q_NULLPTR);
     ~EditGroupWidget();
 
     void loadGroup(Group* group, bool create, Database* database);
diff --git a/src/gui/group/GroupModel.cpp b/src/gui/group/GroupModel.cpp
index 0687d3a68..ec679cd5f 100644
--- a/src/gui/group/GroupModel.cpp
+++ b/src/gui/group/GroupModel.cpp
@@ -27,7 +27,7 @@
 
 GroupModel::GroupModel(Database* db, QObject* parent)
     : QAbstractItemModel(parent)
-    , m_db(0)
+    , m_db(Q_NULLPTR)
 {
     changeDatabase(db);
 }
diff --git a/src/gui/group/GroupModel.h b/src/gui/group/GroupModel.h
index e3565fece..f21bf9ef5 100644
--- a/src/gui/group/GroupModel.h
+++ b/src/gui/group/GroupModel.h
@@ -20,6 +20,8 @@
 
 #include <QtCore/QAbstractItemModel>
 
+#include "core/Global.h"
+
 class Database;
 class Group;
 
@@ -28,7 +30,7 @@ class GroupModel : public QAbstractItemModel
     Q_OBJECT
 
 public:
-    explicit GroupModel(Database* db, QObject* parent = 0);
+    explicit GroupModel(Database* db, QObject* parent = Q_NULLPTR);
     void changeDatabase(Database* newDb);
     QModelIndex index(Group* group) const;
     Group* groupFromIndex(const QModelIndex& index) const;
diff --git a/src/gui/group/GroupView.h b/src/gui/group/GroupView.h
index f9cb9beb7..14b115a15 100644
--- a/src/gui/group/GroupView.h
+++ b/src/gui/group/GroupView.h
@@ -20,6 +20,8 @@
 
 #include <QtGui/QTreeView>
 
+#include "core/Global.h"
+
 class Database;
 class Group;
 class GroupModel;
@@ -29,7 +31,7 @@ class GroupView : public QTreeView
     Q_OBJECT
 
 public:
-    explicit GroupView(Database* db, QWidget* parent = 0);
+    explicit GroupView(Database* db, QWidget* parent = Q_NULLPTR);
     void changeDatabase(Database* newDb);
     void setModel(QAbstractItemModel* model);
     Group* currentGroup();
diff --git a/src/keys/FileKey.h b/src/keys/FileKey.h
index bf3b5d391..e4e67985b 100644
--- a/src/keys/FileKey.h
+++ b/src/keys/FileKey.h
@@ -20,6 +20,7 @@
 
 #include <QtCore/QXmlStreamReader>
 
+#include "core/Global.h"
 #include "keys/Key.h"
 
 class QIODevice;
@@ -29,11 +30,11 @@ class FileKey : public Key
 public:
     FileKey();
     bool load(QIODevice* device);
-    bool load(const QString& fileName, QString* errorMsg = 0);
+    bool load(const QString& fileName, QString* errorMsg = Q_NULLPTR);
     QByteArray rawKey() const;
     FileKey* clone() const;
     static void create(QIODevice* device);
-    static bool create(const QString& fileName, QString* errorMsg = 0);
+    static bool create(const QString& fileName, QString* errorMsg = Q_NULLPTR);
 
 private:
     bool loadXml(QIODevice* device);
diff --git a/tests/TestKeePass2XmlReader.cpp b/tests/TestKeePass2XmlReader.cpp
index 0fde90ef8..d730696b7 100644
--- a/tests/TestKeePass2XmlReader.cpp
+++ b/tests/TestKeePass2XmlReader.cpp
@@ -94,12 +94,12 @@ void TestKeePass2XmlReader::testMetadata()
     QCOMPARE(m_db->metadata()->protectUrl(), true);
     QCOMPARE(m_db->metadata()->protectNotes(), false);
     QCOMPARE(m_db->metadata()->recycleBinEnabled(), true);
-    QVERIFY(m_db->metadata()->recycleBin() != 0);
+    QVERIFY(m_db->metadata()->recycleBin() != Q_NULLPTR);
     QCOMPARE(m_db->metadata()->recycleBin()->name(), QString("Recycle Bin"));
     QCOMPARE(m_db->metadata()->recycleBinChanged(), genDT(2010, 8, 25, 16, 12, 57));
-    QVERIFY(m_db->metadata()->entryTemplatesGroup() == 0);
+    QVERIFY(m_db->metadata()->entryTemplatesGroup() == Q_NULLPTR);
     QCOMPARE(m_db->metadata()->entryTemplatesGroupChanged(), genDT(2010, 8, 8, 17, 24, 19));
-    QVERIFY(m_db->metadata()->lastSelectedGroup() != 0);
+    QVERIFY(m_db->metadata()->lastSelectedGroup() != Q_NULLPTR);
     QCOMPARE(m_db->metadata()->lastSelectedGroup()->name(), QString("NewDatabase"));
     QVERIFY(m_db->metadata()->lastTopVisibleGroup() == m_db->metadata()->lastSelectedGroup());
     QCOMPARE(m_db->metadata()->historyMaxItems(), -1);