diff --git a/docs/black_holes_and_crossmatching.md b/docs/black_holes_and_crossmatching.md
index b16fcad0..a51ca7e6 100644
--- a/docs/black_holes_and_crossmatching.md
+++ b/docs/black_holes_and_crossmatching.md
@@ -39,7 +39,7 @@ Black holes are added to the _tangos_ database with a specialised script that sc
 for black hole particles. Type:
 
 ```
-tangos_add_bh tutorial_changa_blackholes
+tangos_add_bh --sims tutorial_changa_blackholes
 ```
 
 This scans through the timesteps, adds black holes from each snapshot, and links them together using merger
diff --git a/tangos/scripts/add_bh.py b/tangos/scripts/add_bh.py
index b856f6e8..a92fb6e0 100755
--- a/tangos/scripts/add_bh.py
+++ b/tangos/scripts/add_bh.py
@@ -295,7 +295,7 @@ def generate_halolinks(session, fname, pairs):
 def timelink_bh(sims, session):
     query = db.sim_query_from_name_list(sims, session)
     for sim in query.all():
-        pairs = parallel_tasks.distributed(list(zip(sim.timesteps[:-1],sim.timesteps[1:])))
+        pairs = list(zip(sim.timesteps[:-1],sim.timesteps[1:]))
         fname = glob.glob(db.config.base+"/"+sim.basename+"/*.mergers")
         if len(fname)==0:
             logger.error("No merger file for "+sim.basename)