diff --git a/run_sim.py b/run_sim.py
index 796e7350bc3da8b8e72a226b1644ba2f79413cc4..64447998d30c677443171a294408c8c1ba4fc286 100755
--- a/run_sim.py
+++ b/run_sim.py
@@ -8,7 +8,7 @@ import yaml
 import gc
 gc.enable()
 
-def runSim(Catalog):
+def run_sim(Catalog):
     """
     Main method for simulation call.
     """
@@ -59,7 +59,7 @@ def runSim(Catalog):
         chips=config["obs_setting"]["run_chips"])
 
 if __name__=='__main__':
-    runSim(Catalog=Catalog_example)
+    run_sim(Catalog=Catalog_example)
     # To run cycle-3 simulation
     # from Catalog.C3Catalog import C3Catalog
-    # runSim(Catalog=C3Catalog)
+    # run_sim(Catalog=C3Catalog)