diff --git a/src/core/message.cpp b/src/core/message.cpp
index 1c1c72764..4bba43d99 100755
--- a/src/core/message.cpp
+++ b/src/core/message.cpp
@@ -65,7 +65,7 @@ QString Enclosures::encodeEnclosuresToString(const QList<Enclosure> &enclosures)
 }
 
 Message::Message() {
-  m_title = m_url = m_author = m_contents = m_feedId = m_customId = m_customHash = "";
+  m_title = m_url = m_author = m_contents = m_feedId = m_customId = m_customHash = QSL("");
   m_enclosures = QList<Enclosure>();
   m_accountId = m_id = 0;
   m_isRead = m_isImportant = false;
diff --git a/src/core/messagesmodel.cpp b/src/core/messagesmodel.cpp
index d6d9b71d6..3aa9cdd44 100755
--- a/src/core/messagesmodel.cpp
+++ b/src/core/messagesmodel.cpp
@@ -74,7 +74,7 @@ void MessagesModel::loadMessages(RootItem *item) {
   }
   else {
     if (!item->getParentServiceRoot()->loadMessagesForItem(item, this)) {
-      setFilter("true != true");
+      setFilter(QSL("true != true"));
       qWarning("Loading of messages from item '%s' failed.", qPrintable(item->title()));
       qApp->showGuiMessage(tr("Loading of messages from item '%1' failed.").arg(item->title()),
                            tr("Loading of messages failed, maybe messages could not be downloaded."),
@@ -201,7 +201,7 @@ QVariant MessagesModel::data(const QModelIndex &idx, int role) const {
       else if (index_column == MSG_DB_AUTHOR_INDEX) {
         const QString author_name = QSqlTableModel::data(idx, role).toString();
 
-        return author_name.isEmpty() ? "-" : author_name;
+        return author_name.isEmpty() ? QSL("-") : author_name;
       }
       else if (index_column != MSG_DB_IMPORTANT_INDEX && index_column != MSG_DB_READ_INDEX) {
         return QSqlTableModel::data(idx, role);
diff --git a/src/dynamic-shortcuts/shortcutbutton.cpp b/src/dynamic-shortcuts/shortcutbutton.cpp
index d298e1b5c..8550abb33 100755
--- a/src/dynamic-shortcuts/shortcutbutton.cpp
+++ b/src/dynamic-shortcuts/shortcutbutton.cpp
@@ -72,7 +72,8 @@ void ShortcutButton::keyPressEvent(QKeyEvent *event) {
   }
 
   if (!m_catcher->m_isRecording) {
-    return QPushButton::keyPressEvent(event);
+    QPushButton::keyPressEvent(event);
+    return;
   }
 
   event->accept();
@@ -124,7 +125,8 @@ void ShortcutButton::keyReleaseEvent(QKeyEvent *event) {
   }
 
   if (!m_catcher->m_isRecording) {
-    return QPushButton::keyReleaseEvent(event);
+    QPushButton::keyReleaseEvent(event);
+    return;
   }
 
   event->accept();
diff --git a/src/gui/basetoolbar.cpp b/src/gui/basetoolbar.cpp
index f0239bf75..a4124a5d4 100755
--- a/src/gui/basetoolbar.cpp
+++ b/src/gui/basetoolbar.cpp
@@ -35,7 +35,7 @@ BaseToolBar::~BaseToolBar() {
   qDebug("Destroying BaseToolBar instance.");
 }
 
-QAction *BaseBar::findMatchingAction(const QString &action, const QList<QAction*> actions) const {
+QAction *BaseBar::findMatchingAction(const QString &action, const QList<QAction*> &actions) const {
   foreach (QAction *act, actions) {
     if (act->objectName() == action) {
       return act;
diff --git a/src/gui/basetoolbar.h b/src/gui/basetoolbar.h
index 4c4032b32..4b5c91309 100755
--- a/src/gui/basetoolbar.h
+++ b/src/gui/basetoolbar.h
@@ -38,7 +38,7 @@ class BaseBar {
     virtual void loadChangeableActions() = 0;
 
   protected:
-    QAction *findMatchingAction(const QString &action, const QList<QAction*> actions) const;
+    QAction *findMatchingAction(const QString &action, const QList<QAction *> &actions) const;
 };
 
 class BaseToolBar : public QToolBar, public BaseBar {
diff --git a/src/gui/dialogs/formmain.cpp b/src/gui/dialogs/formmain.cpp
index d0dd28fa4..6adb427b2 100755
--- a/src/gui/dialogs/formmain.cpp
+++ b/src/gui/dialogs/formmain.cpp
@@ -191,7 +191,7 @@ void FormMain::prepareMenus() {
 #if defined(Q_OS_WIN)
     m_trayMenu = new TrayIconMenu(APP_NAME, this);
 #else
-    m_trayMenu = new QMenu(APP_NAME, this);
+    m_trayMenu = new QMenu(QSL(APP_NAME), this);
 #endif
 
     // Add needed items to the menu.
@@ -252,7 +252,7 @@ void FormMain::updateAddItemMenu() {
                                              m_ui->m_menuAddItem);
       root_menu->addAction(action_new_feed);
       // NOTE: Because of default arguments.
-      connect(action_new_feed, SIGNAL(triggered()), activated_root, SLOT(addNewFeed()));
+      connect(action_new_feed, SIGNAL(triggered(bool)), activated_root, SLOT(addNewFeed()));
     }
 
     if (!specific_root_actions.isEmpty()) {
@@ -349,7 +349,7 @@ void FormMain::updateAccountsMenu() {
   m_ui->m_menuAccounts->addAction(m_ui->m_actionServiceDelete);
 }
 
-void FormMain::onFeedUpdatesFinished(FeedDownloadResults results) {
+void FormMain::onFeedUpdatesFinished(const FeedDownloadResults &results) {
   Q_UNUSED(results)
 
   statusBar()->clearProgressFeeds();
diff --git a/src/gui/dialogs/formmain.h b/src/gui/dialogs/formmain.h
index f47180082..74de8a6fe 100755
--- a/src/gui/dialogs/formmain.h
+++ b/src/gui/dialogs/formmain.h
@@ -75,7 +75,7 @@ class FormMain : public QMainWindow {
 
     void onFeedUpdatesStarted();
     void onFeedUpdatesProgress(const Feed *feed, int current, int total);
-    void onFeedUpdatesFinished(FeedDownloadResults results);
+    void onFeedUpdatesFinished(const FeedDownloadResults &results);
 
     // Displays various dialogs.
     void backupDatabaseSettings();
diff --git a/src/services/standard/standardfeed.h b/src/services/standard/standardfeed.h
index ff57235a6..2934d55f9 100755
--- a/src/services/standard/standardfeed.h
+++ b/src/services/standard/standardfeed.h
@@ -87,7 +87,7 @@ class StandardFeed : public Feed {
       return m_type;
     }
 
-    inline void setType(const Type &type) {
+    inline void setType(Type type) {
       m_type = type;
     }