diff --git a/wetb/prepost/Simulations.py b/wetb/prepost/Simulations.py
index 9f80d3356acf42eb72351f8b26bd6e2b3fbaa544..d20bd8f31c9b7f7e1a5c4abd5938eb30afa5e4a8 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))