diff --git a/components/groundstation.py b/components/groundstation.py
index 81fac33a0ec0b81828c5881c87e79cbab22a9615..b6597626e86743ed542e27ddbc956ea4834d325b 100644
--- a/components/groundstation.py
+++ b/components/groundstation.py
@@ -33,7 +33,7 @@ ncoords = len(args.coords)
 grid = UnstructuredGrid("pamtra-grid", [3]*ncoords,
                         [*coords[:,0], *(coords[:,0]+0.1), *coords[:,0]],
                         [*coords[:,1], *coords[:,1], *(coords[:,1]+0.1)],
-                        np.array(zip(range(ncoords), range(ncoords, 2*ncoords), range(2*ncoords, 3*ncoords))))
+                        np.array(list(zip(range(ncoords), range(ncoords, 2*ncoords), range(2*ncoords, 3*ncoords)))))
 points = grid.def_points(Location.CELL,
                          coords[:,0], coords[:,1])