diff --git a/kstyle/breezestyle.h b/kstyle/breezestyle.h
--- a/kstyle/breezestyle.h
+++ b/kstyle/breezestyle.h
@@ -92,14 +92,16 @@
 
         //* needed to avoid warnings at compilation time
         using  ParentStyleClass::polish;
-        using  ParentStyleClass::unpolish;
 
         //* widget polishing
         virtual void polish( QWidget* );
 
         //* widget unpolishing
         virtual void unpolish( QWidget* );
 
+        //* application unpolishing
+        void unpolish( QApplication* ) override;
+
         //* polish scrollarea
         void polishScrollArea( QAbstractScrollArea* );
 
@@ -471,6 +473,9 @@
 
         private:
 
+        //* shared cleanup for unpolish and dtor
+        void cleanup();
+
         //*@name scrollbar button types (for addLine and subLine )
         //@{
         ScrollBarButtonType _addLineButtons;
diff --git a/kstyle/breezestyle.cpp b/kstyle/breezestyle.cpp
--- a/kstyle/breezestyle.cpp
+++ b/kstyle/breezestyle.cpp
@@ -198,8 +198,23 @@
     //______________________________________________________________
     Style::~Style( void )
     {
+        cleanup();
+    }
+
+    //______________________________________________________________
+    void Style::unpolish( QApplication* )
+    {
+        // NOTE: unpolish is not called in general on tear-down of Application
+        // only when a new QStyle is loaded by the QApplication unpolish is invoked
+        cleanup();
+    }
+
+    void Style::cleanup( void )
+    {
         delete _shadowHelper;
+        _shadowHelper = nullptr;
         delete _helper;
+        _helper = nullptr;
     }
 
     //______________________________________________________________