diff --git a/src/Mod/Sketcher/App/planegcs/Geo.h b/src/Mod/Sketcher/App/planegcs/Geo.h
index 44664c7d08..1cdb983347 100644
--- a/src/Mod/Sketcher/App/planegcs/Geo.h
+++ b/src/Mod/Sketcher/App/planegcs/Geo.h
@@ -28,7 +28,14 @@
 
 namespace GCS
 {
-    class Point
+    class DependentParameters 
+    {
+    public:
+        DependentParameters():hasDependentParameters(false) {}
+        bool hasDependentParameters;
+    };
+    
+    class Point : public DependentParameters
     {
     public:
         Point(){x = 0; y = 0;}
@@ -88,7 +95,7 @@ namespace GCS
     // Geometries
     ///////////////////////////////////////
 
-    class Curve //a base class for all curve-based objects (line, circle/arc, ellipse/arc)
+    class Curve: public DependentParameters //a base class for all curve-based objects (line, circle/arc, ellipse/arc)
     {
     public:
         virtual ~Curve(){}