diff --git a/simulation.py b/simulation.py
index 5d5e1d4..2323670 100644
--- a/simulation.py
+++ b/simulation.py
@@ -1013,7 +1013,7 @@ def run_simulation(name: str, simulation_type: str, modify_pattern_start_time: s
     time.sleep(5)  # wait 50 seconds
     
     tmp_file = './temp/simulation.result.out'
-    shutil.copy(f'./temp/{name_c}.db.out', tmp_file)
+    shutil.copy(f'./temp/{name_c}.db.opt', tmp_file)
     output = Output(tmp_file)
     node_result = output.node_results()
     link_result = output.link_results()