diff --git a/Gui/VtkVis/VtkPolylinesSource.cpp b/Gui/VtkVis/VtkPolylinesSource.cpp
index 1f7cadf327dff353ecf69af1b21910f633e24077..583ea0370e76eb563f56deabf71301f378f475d3 100644
--- a/Gui/VtkVis/VtkPolylinesSource.cpp
+++ b/Gui/VtkVis/VtkPolylinesSource.cpp
@@ -10,6 +10,10 @@
  */
 
 // ** INCLUDES **
+// GeoLib
+#include "Color.h"
+#include "Polyline.h"
+
 #include "VtkPolylinesSource.h"
 
 #include <vtkCellArray.h>
diff --git a/Gui/VtkVis/VtkPolylinesSource.h b/Gui/VtkVis/VtkPolylinesSource.h
index 43ec7bbde9ba84f41bbc2d58b053362635dad883..3f843503545b0c254127048ebaa6c5b825274093 100644
--- a/Gui/VtkVis/VtkPolylinesSource.h
+++ b/Gui/VtkVis/VtkPolylinesSource.h
@@ -16,7 +16,11 @@
 #include "VtkAlgorithmProperties.h"
 #include <vtkPolyDataAlgorithm.h>
 
-#include "GEOObjects.h"
+// forward declaration
+namespace GeoLib {
+class Polyline;
+}
+
 
 /**
  * \brief VtkPolylinesSource is a VTK source object for the visualisation of