diff --git a/wetb/prepost/Simulations.py b/wetb/prepost/Simulations.py
index ff1212b11f4b6698954f1d84db5ecd8e117a1682..89ea46e44eba842512627b41f3a85737de1fbb29 100755
--- a/wetb/prepost/Simulations.py
+++ b/wetb/prepost/Simulations.py
@@ -5127,7 +5127,7 @@ class Cases(object):
             print('='*79)
             print('statistics for %s, nr cases: %i' % (sim_id, nrcases))
 
-        fname = os.path.join(post_dir, sim_id, '_envelope' + append + '.h5')
+        fname = os.path.join(post_dir, sim_id + '_envelope' + append + '.h5')
         h5f = tbl.openFile(fname, mode="w", title=str(sim_id),
                            filters=tbl.Filters(complevel=9))