diff --git a/build_pop.py b/build_pop.py
index d859cf882d187e910821bede97828c9e28aed6a2..244cb6089052177f8864d6869aed08681e1eaf67 100755
--- a/build_pop.py
+++ b/build_pop.py
@@ -605,9 +605,8 @@ def init(output_dir, force_outputdir, sv_list, nstretches, nb_inds, reference, p
         ok = True
         if genotypes is None:
             if quiet:
-                with open(os.path.join(output_dir, "confirm.txt"), "w") as log_file:
-                    printer_confirm = Print(stdout=log_file, stderr=stderr)
-                    ok = confirm(deletions, inversions, sv_sim.variants, printer_confirm, False)
+                printer_confirm = Print(stdout=os.path.join(output_dir, "confirm.txt"), stderr=stderr)
+                ok = confirm(deletions, inversions, sv_sim.variants, printer_confirm, False)
             else:
                 ok = confirm(deletions, inversions, sv_sim.variants, printer_confirm)
         if ok: