diff --git a/src/filter/filteractions/filteraction.h b/src/filter/filteractions/filteraction.h
index 8ec3769f22e5dbdd752402802209dd80d578cf93..ab6568372160f528b1d1d20e5e96d9f709087a80 100644
--- a/src/filter/filteractions/filteraction.h
+++ b/src/filter/filteractions/filteraction.h
@@ -182,8 +182,8 @@ Q_SIGNALS:
     void filterActionModified();
 
 private:
-    QString mName;
-    QString mLabel;
+    const QString mName;
+    const QString mLabel;
 };
 }
 
diff --git a/src/filter/filterconverter/filterconverttosieve.h b/src/filter/filterconverter/filterconverttosieve.h
index 6bbbdd62b0bf6a0de78e270423721d6c14a421a0..78db6e0f41635bf0a14a5caf5133c3be8dc6e27c 100644
--- a/src/filter/filterconverter/filterconverttosieve.h
+++ b/src/filter/filterconverter/filterconverttosieve.h
@@ -20,7 +20,7 @@ public:
     void convert();
 
 private:
-    QVector<MailFilter *> mListFilters;
+    const QVector<MailFilter *> mListFilters;
 };
 }
 #endif // FILTERCONVERTTOSIEVE_H
diff --git a/src/filter/mdnadvicedialog.cpp b/src/filter/mdnadvicedialog.cpp
index 11b2c89c96a51dd8e79e145de9ec8947ffbe36c0..b129172d8d4211df42322b29d7db254aeeaaefe4 100644
--- a/src/filter/mdnadvicedialog.cpp
+++ b/src/filter/mdnadvicedialog.cpp
@@ -85,7 +85,6 @@ static const int numMdnMessageBoxes
 
 MDNAdviceDialog::MDNAdviceDialog(const QString &text, bool canDeny, QWidget *parent)
     : QDialog(parent)
-    , m_result(MessageComposer::MDNIgnore)
 {
     setWindowTitle(i18nc("@title:window", "Message Disposition Notification Request"));
     QPushButton *user1Button = nullptr;
diff --git a/src/filter/mdnadvicedialog.h b/src/filter/mdnadvicedialog.h
index a80ff456c933c1c8e0d1147a442763cb37e3e93d..6875e2db46804f24be875dd951dde5e24e5f2658 100644
--- a/src/filter/mdnadvicedialog.h
+++ b/src/filter/mdnadvicedialog.h
@@ -76,7 +76,7 @@ private:
     void slotUser1Clicked();
     void slotUser2Clicked();
     void slotYesClicked();
-    MessageComposer::MDNAdvice m_result;
+    MessageComposer::MDNAdvice m_result = MessageComposer::MDNIgnore;
 
 protected:
 
diff --git a/src/kernel/mailkernel.cpp b/src/kernel/mailkernel.cpp
index 17a6d8b1ab31bf283b18071ff39ab6eb0d3cbda4..0f526969e7af5d786971e87bf73f5d41d51f32f4 100644
--- a/src/kernel/mailkernel.cpp
+++ b/src/kernel/mailkernel.cpp
@@ -39,7 +39,7 @@ public:
         delete kernel;
     }
 
-    Kernel *kernel;
+    Kernel *const kernel;
 };
 
 Q_GLOBAL_STATIC(KernelPrivate, sInstance)
diff --git a/src/search/widgethandler/rulewidgethandlermanager.cpp b/src/search/widgethandler/rulewidgethandlermanager.cpp
index 1ca792fff8f719d4301a6d28c83068b811a8764a..a7a72ef4ea94e339b729226ca30e27988d1191bb 100644
--- a/src/search/widgethandler/rulewidgethandlermanager.cpp
+++ b/src/search/widgethandler/rulewidgethandlermanager.cpp
@@ -33,7 +33,6 @@ using namespace MailCommon;
 MailCommon::RuleWidgetHandlerManager *MailCommon::RuleWidgetHandlerManager::self = nullptr;
 
 MailCommon::RuleWidgetHandlerManager::RuleWidgetHandlerManager()
-    : mIsBalooSearch(false)
 {
     registerHandler(new MailCommon::TagRuleWidgetHandler());
     registerHandler(new MailCommon::DateRuleWidgetHandler());
diff --git a/src/search/widgethandler/rulewidgethandlermanager.h b/src/search/widgethandler/rulewidgethandlermanager.h
index f0d90bd4fe0776bb220cf3c72d66f4ac4bc40b2f..98eacef56bc6b9aac81d58280e7b7d4896dae8b6 100644
--- a/src/search/widgethandler/rulewidgethandlermanager.h
+++ b/src/search/widgethandler/rulewidgethandlermanager.h
@@ -66,7 +66,7 @@ private:
     typedef QVector<const RuleWidgetHandler *>::iterator iterator;
 
     QVector<const RuleWidgetHandler *> mHandlers;
-    bool mIsBalooSearch;
+    bool mIsBalooSearch = false;
 };
 } // namespace MailCommon
 
diff --git a/src/search/widgethandler/tagrulewidgethandler.cpp b/src/search/widgethandler/tagrulewidgethandler.cpp
index 8ef6517e6cea2bc248c147c1d6bf8b71facbd3b7..86e6ba68d9c0d03ed03548a728fad73e8480e980 100644
--- a/src/search/widgethandler/tagrulewidgethandler.cpp
+++ b/src/search/widgethandler/tagrulewidgethandler.cpp
@@ -35,7 +35,7 @@ private Q_SLOTS:
     void onTagsFetched(KJob *);
 
 private:
-    QComboBox * mComboBox = nullptr;
+    QComboBox *mComboBox = nullptr;
 };
 
 FillTagComboJob::FillTagComboJob(QComboBox *combo, QObject *parent)
diff --git a/src/snippets/snippetvariabledialog.h b/src/snippets/snippetvariabledialog.h
index b1744cd8fc662c7e222e1a85338b4c96eb310530..60cca76b9d7022592d3819cc6fe36fd413b4c3e2 100644
--- a/src/snippets/snippetvariabledialog.h
+++ b/src/snippets/snippetvariabledialog.h
@@ -32,7 +32,7 @@ private:
     void writeConfig();
     void readConfig();
     void slotAccepted();
-    QString mVariableName;
+    const QString mVariableName;
     QMap<QString, QString> *mVariables = nullptr;
     KPIMTextEdit::PlainTextEditorWidget *mVariableValueText = nullptr;
     QCheckBox *mSaveVariable = nullptr;