diff --git a/README.md b/README.md
index 15393d2..e164474 100644
--- a/README.md
+++ b/README.md
@@ -71,7 +71,10 @@ Now you are back in terminal and ready to build.
```
> make
```
-In order to extend the supported DICOM formats, the library vtk-dicom USE_VTK_DICOM
can be optionally enabled (see https://github.com/dgobbi/vtk-dicom).
+In order to extend the supported DICOM formats, the library vtk-dicom USE_VTK_DICOM
can be optionally enabled (see https://github.com/dgobbi/vtk-dicom). If you use VTK 6, 7 or 8, you have to build vtk-dicom separately. From on VTK 9, vtk-dicom is part of the vtk project - you can enable the corresponding module when building VTK with
+```
+> cmake .. -DVTK_MODULE_ENABLE_VTK_DICOM=YES -DVTK_MODULE_ENABLE_VTK_vtkDICOM=YES
+```
Building on Windows:
@@ -111,7 +114,7 @@ The icons in the gui were made by