diff --git a/config/config.default.yaml b/config/config.default.yaml
index f68ff960..5e204a95 100644
--- a/config/config.default.yaml
+++ b/config/config.default.yaml
@@ -418,10 +418,10 @@ sector:
       heat_loss: 0.0
   heat_pump_sources:
     central_heating:
-      - air
+    - air
     decentral_heating:
-      - air
-      - ground
+    - air
+    - ground
   cluster_heat_buses: true
   heat_demand_cutout: default
   bev_dsm_restriction_value: 0.75
diff --git a/rules/build_sector.smk b/rules/build_sector.smk
index d6f959f3..dbba8805 100644
--- a/rules/build_sector.smk
+++ b/rules/build_sector.smk
@@ -237,9 +237,12 @@ rule build_cop_profiles:
         temp_soil_total=resources("temp_soil_total_elec_s{simpl}_{clusters}.nc"),
         temp_air_total=resources("temp_air_total_elec_s{simpl}_{clusters}.nc"),
     output:
-        **{f"cop_{source}_{sink}": resources(
-            "cop_" + source + "_" + {sink} + "_" + "elec_s{simpl}_{clusters}.nc"
-        ) for sink, source in config_provider("sector", "heat_pump_sources").items()},
+        **{
+            f"cop_{source}_{sink}": resources(
+                "cop_" + source + "_" + {sink} + "_" + "elec_s{simpl}_{clusters}.nc"
+            )
+            for sink, source in config_provider("sector", "heat_pump_sources").items()
+        },
         # cop_air_decentral_heating=resources(
         #     "cop_air_decentral_heating_elec_s{simpl}_{clusters}.nc"
         # ),