diff --git a/vtr_flow/scripts/tuning_runs/control_runs.py b/vtr_flow/scripts/tuning_runs/control_runs.py
index c50e93a8bb1..5bc9c25036b 100755
--- a/vtr_flow/scripts/tuning_runs/control_runs.py
+++ b/vtr_flow/scripts/tuning_runs/control_runs.py
@@ -165,6 +165,7 @@ def parse_script_params(script_params):
 def generate_avg_seed_csv(full_res_csv_path, output_dir):
     """Generate the average results over the seeds"""
     df = pd.read_csv(full_res_csv_path)
+    assert isinstance(df, pd.DataFrame)
 
     if KEEP_METRICS_ONLY:
         col_to_keep = ["circuit", "arch"]