diff --git a/examples/11_plurigaussian/04_3d_pgs.py b/examples/11_plurigaussian/04_3d_pgs.py
index f3ff130b..34a03841 100644
--- a/examples/11_plurigaussian/04_3d_pgs.py
+++ b/examples/11_plurigaussian/04_3d_pgs.py
@@ -63,7 +63,7 @@
 # grid.point_data['L'] = np.meshgrid(L, indexing="ij")[0]
 # grid.plot(show_edges=True)
 
-grid.point_data['PGS'] = pgs.P.reshape(-1)
+grid.point_data["PGS"] = pgs.P.reshape(-1)
 grid.contour(isosurfaces=8).plot()
 
 ###############################################################################