diff --git a/rules/solve_perfect.smk b/rules/solve_perfect.smk
index a06c6dfa..4db4e31a 100644
--- a/rules/solve_perfect.smk
+++ b/rules/solve_perfect.smk
@@ -25,6 +25,7 @@ rule add_existing_baseyear:
             "existing_heating_distribution_elec_s{simpl}_{clusters}_{planning_horizons}.csv"
         ),
         existing_heating="data/existing_infrastructure/existing_heating_raw.csv",
+        heating_efficiencies=resources("heating_efficiencies.csv"),
     output:
         RESULTS
         + "prenetworks-brownfield/elec_s{simpl}_{clusters}_l{ll}_{opts}_{sector_opts}_{planning_horizons}.nc",