diff --git a/setup.py b/setup.py
index cadb3189c..bed21c838 100644
--- a/setup.py
+++ b/setup.py
@@ -23,11 +23,11 @@ def get_extensions():
     voxel_boundary_intersection =\
         Extension('scilpy.tractanalysis.voxel_boundary_intersection',
                   ['scilpy/tractanalysis/voxel_boundary_intersection.pyx'],
-                                            define_macros=define_macros)
+                  define_macros=define_macros)
     streamlines_metrics =\
         Extension('scilpy.tractanalysis.streamlines_metrics',
                   ['scilpy/tractanalysis/streamlines_metrics.pyx'],
-                                    define_macros=define_macros)
+                  define_macros=define_macros)
     return [uncompress, voxel_boundary_intersection, streamlines_metrics]