diff --git a/src/filter/mdnadvicedialog.cpp b/src/filter/mdnadvicedialog.cpp
index d2cc160..3dd66aa 100644
--- a/src/filter/mdnadvicedialog.cpp
+++ b/src/filter/mdnadvicedialog.cpp
@@ -5,11 +5,8 @@
 */
 
 #include "mdnadvicedialog.h"
-#include "kernel/mailkernel.h"
 #include "mailcommon_debug.h"
 
-#include <MimeTreeParser/ObjectTreeParser>
-
 #include <KLocalizedString>
 #include <KMessageBox>
 
diff --git a/src/filter/mdnadvicedialog.h b/src/filter/mdnadvicedialog.h
index 8fdd08b..9ae9233 100644
--- a/src/filter/mdnadvicedialog.h
+++ b/src/filter/mdnadvicedialog.h
@@ -19,10 +19,10 @@ class MAILCOMMON_EXPORT MDNAdviceDialog : public QDialog
     Q_OBJECT
 
 public:
-    MDNAdviceDialog(const QString &text, bool canDeny, QWidget *parent = nullptr);
+    explicit MDNAdviceDialog(const QString &text, bool canDeny, QWidget *parent = nullptr);
     ~MDNAdviceDialog();
 
-    MessageComposer::MDNAdvice result() const;
+    Q_REQUIRED_RESULT MessageComposer::MDNAdvice result() const;
 
 private:
     void slotUser1Clicked();
@@ -30,10 +30,6 @@ private:
     void slotYesClicked();
     MessageComposer::MDNAdvice m_result = MessageComposer::MDNIgnore;
 
-protected:
-
-    // Reimplemented
-    void slotButtonClicked(int button);
 };
 }