diff --git a/tax_microdata_benchmarking/create_flat_file.py b/tax_microdata_benchmarking/create_flat_file.py
index 758dc066..adc6dc35 100644
--- a/tax_microdata_benchmarking/create_flat_file.py
+++ b/tax_microdata_benchmarking/create_flat_file.py
@@ -808,7 +808,7 @@ def summary_analytics(df):
     return summary_df
 
 
-population = system.calibration.census.populations.total
+population = system.parameters.calibration.census.populations.total
 
 
 if __name__ == "__main__":