diff --git a/invesalius/reader/dicom_reader.py b/invesalius/reader/dicom_reader.py
index cc36bf5..b71695a 100644
--- a/invesalius/reader/dicom_reader.py
+++ b/invesalius/reader/dicom_reader.py
@@ -118,6 +118,13 @@ def yGetDicomGroups(directory, recursive=True, gui=True):
     yield grouper.GetPatientsGroups()
 
 def GetDicomGroups(directory, recursive=True):
+    
+    if not const.VTK_WARNING:
+        fow = vtk.vtkFileOutputWindow()
+        #fow.SetFileName('c:\\vtkoutput.txt')
+        ow = vtk.vtkOutputWindow()
+        ow.SetInstance(fow)
+        
     return yGetDicomGroups(directory, recursive, gui=False).next()
 
 
@@ -145,12 +152,6 @@ class ProgressDicomReader:
 
     def GetDicomGroups(self, path, recursive):
         
-        if not const.VTK_WARNING:
-            fow = vtk.vtkFileOutputWindow()
-            #fow.SetFileName('c:\\vtkoutput.txt')
-            ow = vtk.vtkOutputWindow()
-            ow.SetInstance(fow)
-        
         y = yGetDicomGroups(path, recursive)
         for value_progress in y:
             if not self.running:
--
libgit2 0.21.2