diff --git a/invesalius/data/polydata_utils.py b/invesalius/data/polydata_utils.py
index e9969eb..b71f5d3 100644
--- a/invesalius/data/polydata_utils.py
+++ b/invesalius/data/polydata_utils.py
@@ -108,7 +108,7 @@ def Merge(polydata_list):
     append = vtk.vtkAppendPolyData()
 
     for polydata in polydata_list:
-        triangle = vtk.TriangleFilter()
+        triangle = vtk.vtkTriangleFilter()
         triangle.SetInput(polydata)
         append.AddInput(triangle.GetOutput())
 
--
libgit2 0.21.2