diff --git a/Snakefile b/Snakefile
index 2c342efc..a59025f9 100644
--- a/Snakefile
+++ b/Snakefile
@@ -47,7 +47,6 @@ RESULTS = "results/" + RDIR
 #     RESOURCES = "resources/"
 
 
-
 localrules:
     purge,
 
diff --git a/rules/solve_perfect.smk b/rules/solve_perfect.smk
index 723fd6a7..3bb006c5 100644
--- a/rules/solve_perfect.smk
+++ b/rules/solve_perfect.smk
@@ -15,7 +15,7 @@ rule add_existing_baseyear:
         busmap=resources("busmap_elec_s{simpl}_{clusters}.csv"),
         clustered_pop_layout=resources("pop_layout_elec_s{simpl}_{clusters}.csv"),
         costs=resources("costs_{}.csv".format(
-            config_provider("scenario", "planning_horizons", 0)
+            config_provider("scenario", "planning_horizons", 0)(w)
         )),
         cop_soil_total=resources("cop_soil_total_elec_s{simpl}_{clusters}.nc"),
         cop_air_total=resources("cop_air_total_elec_s{simpl}_{clusters}.nc"),
diff --git a/scripts/plot_summary.py b/scripts/plot_summary.py
index f0d80176..4119a811 100644
--- a/scripts/plot_summary.py
+++ b/scripts/plot_summary.py
@@ -584,8 +584,8 @@ if __name__ == "__main__":
 
     plot_balances()
 
+    co2_budget = snakemake.params["co2_budget"]
     if (
-        snakemake.params["co2_budget"].startswith("cb")
-        or snakemake.params["foresight"] == "perfect"
-    ):
+        isinstance(co2_budget, str) and co2_budget.startswith("cb")
+    ) or snakemake.params["foresight"] == "perfect":
         plot_carbon_budget_distribution(snakemake.input.eurostat)
diff --git a/scripts/prepare_network.py b/scripts/prepare_network.py
index e1b42243..6b782d44 100755
--- a/scripts/prepare_network.py
+++ b/scripts/prepare_network.py
@@ -62,7 +62,11 @@ import logging
 import numpy as np
 import pandas as pd
 import pypsa
-from _helpers import configure_logging, update_config_from_wildcards, set_scenario_config
+from _helpers import (
+    configure_logging,
+    set_scenario_config,
+    update_config_from_wildcards,
+)
 from add_electricity import load_costs, update_transmission_costs
 from pypsa.descriptors import expand_series