diff --git a/src/Mod/Sketcher/Gui/DrawSketchController.h b/src/Mod/Sketcher/Gui/DrawSketchController.h
index 6e4bde1a3e..f65ebe3b48 100644
--- a/src/Mod/Sketcher/Gui/DrawSketchController.h
+++ b/src/Mod/Sketcher/Gui/DrawSketchController.h
@@ -118,18 +118,12 @@ public:
     //@}
 
 protected:
-    HandlerT* handler;           // real derived type
-    bool init = false;           // true if the controls have been initialised.
-    bool firstMoveInit = false;  // true if first mouse movement not yet performed (resets)
-
-    std::unique_ptr<DrawSketchKeyboardManager> keymanager;
-
-    Base::Vector2d prevCursorPosition;
-    Base::Vector2d lastControlEnforcedPosition;
-
-    int onViewIndexWithFocus = 0;  // track the index of the on-view parameter having the focus
-    int nOnViewParameter = OnViewParametersT::defaultMethodSize();
+    // NOLINTBEGIN
+    HandlerT* handler;  // real derived type
+    std::vector<std::unique_ptr<Gui::EditableDatumLabel>> onViewParameters;
+    // NOLINTEND
 
+    bool init = false;  // true if the controls have been initialised.
 
     /** @name Named indices for controlling on-view controls */
     //@{
@@ -149,7 +143,12 @@ protected:
     };
     //@}
 
-    std::vector<std::unique_ptr<Gui::EditableDatumLabel>> onViewParameters;
+private:
+    Base::Vector2d prevCursorPosition;
+    Base::Vector2d lastControlEnforcedPosition;
+
+    int onViewIndexWithFocus = 0;  // track the index of the on-view parameter having the focus
+    int nOnViewParameter = OnViewParametersT::defaultMethodSize();
 
     /// Class to keep track of colors used by the on-view parameters
     class ColorManager
@@ -262,8 +261,8 @@ public:
 
     DrawSketchController(const DrawSketchController&) = delete;
     DrawSketchController(DrawSketchController&&) = delete;
-    bool operator=(const DrawSketchController&) = delete;
-    bool operator=(DrawSketchController&&) = delete;
+    DrawSketchController& operator=(const DrawSketchController&) = delete;
+    DrawSketchController& operator=(DrawSketchController&&) = delete;
 
     virtual ~DrawSketchController()
     {}
@@ -725,6 +724,13 @@ protected:
     }
     //@}
 
+    // makes keymanager available to derived classes so that they install it as event handler
+    // where necessary, without allowing them to manage resource ownership
+    DrawSketchKeyboardManager* getKeyManager()
+    {
+        return keymanager.get();
+    }
+
 private:
     /** @name helper functions */
     //@{
@@ -744,6 +750,9 @@ private:
 private:
     OnViewParameterVisibilityManager ovpVisibilityManager;
     ColorManager colorManager;
+    std::unique_ptr<DrawSketchKeyboardManager> keymanager;
+
+    bool firstMoveInit = false;  // true if first mouse movement not yet performed (resets)
 };
 
 
diff --git a/src/Mod/Sketcher/Gui/DrawSketchDefaultWidgetController.h b/src/Mod/Sketcher/Gui/DrawSketchDefaultWidgetController.h
index 2c916e7e55..4df96a6b4c 100644
--- a/src/Mod/Sketcher/Gui/DrawSketchDefaultWidgetController.h
+++ b/src/Mod/Sketcher/Gui/DrawSketchDefaultWidgetController.h
@@ -91,7 +91,7 @@ public:
                                                 ConstructionMethodT>;
     //@}
 
-protected:
+private:
     int nParameter = WidgetParametersT::defaultMethodSize();
     int nCheckbox = WidgetCheckboxesT::defaultMethodSize();
     int nCombobox = WidgetComboboxesT::defaultMethodSize();
@@ -117,8 +117,14 @@ protected:
 public:
     explicit DrawSketchDefaultWidgetController(HandlerT* dshandler)
         : ControllerBase(dshandler)
+        , toolWidget(nullptr)
     {}
 
+    DrawSketchDefaultWidgetController(const DrawSketchDefaultWidgetController&) = delete;
+    DrawSketchDefaultWidgetController(DrawSketchDefaultWidgetController&&) = delete;
+    DrawSketchDefaultWidgetController& operator=(const DrawSketchDefaultWidgetController&) = delete;
+    DrawSketchDefaultWidgetController& operator=(DrawSketchDefaultWidgetController&&) = delete;
+
     ~DrawSketchDefaultWidgetController() override
     {
         connectionParameterValueChanged.disconnect();
@@ -262,7 +268,7 @@ private:
     /// Initialisation of the widget
     void initDefaultWidget(QWidget* widget)
     {
-        toolWidget = static_cast<SketcherToolDefaultWidget*>(widget);
+        toolWidget = static_cast<SketcherToolDefaultWidget*>(widget);  // NOLINT
 
         connectionParameterValueChanged = toolWidget->registerParameterValueChanged(
             std::bind(&DrawSketchDefaultWidgetController::parameterValueChanged,
@@ -294,7 +300,7 @@ private:
         nCheckbox = WidgetCheckboxesT::size(handler->constructionMethod());
         nCombobox = WidgetComboboxesT::size(handler->constructionMethod());
 
-        toolWidget->initNParameters(nParameter, keymanager.get());
+        toolWidget->initNParameters(nParameter, ControllerBase::getKeyManager());
         toolWidget->initNCheckboxes(nCheckbox);
         toolWidget->initNComboboxes(nCombobox);