diff --git a/config.default.yaml b/config.default.yaml
index 8ea82891..ecb9f201 100755
--- a/config.default.yaml
+++ b/config.default.yaml
@@ -45,6 +45,7 @@ electricity:
   agg_p_nom_limits: data/agg_p_nom_minmax.csv
 
   operational_reserve: # like https://genxproject.github.io/GenX/dev/core/#Reserves
+    activate: true
     epsilon_load: 0.02 # share of total load
     epsilon_vres: 0.02 # share of total renewable supply
     contingency: 4000 # fixed capacity in MW
diff --git a/scripts/solve_network.py b/scripts/solve_network.py
index a13b1531..0398dce0 100755
--- a/scripts/solve_network.py
+++ b/scripts/solve_network.py
@@ -304,7 +304,8 @@ def extra_functionality(n, snapshots):
         add_SAFE_constraints(n, config)
     if 'CCL' in opts and n.generators.p_nom_extendable.any():
         add_CCL_constraints(n, config)
-    if config["electricity"].get("operational_reserve"):
+    reserve = config["electricity"].get("operational_reserve", {})
+    if reserve.get("activate"):
         add_operational_reserve_margin(n, snapshots, config)
     for o in opts:
         if "EQ" in o: