diff --git a/scripts/prepare_network.py b/scripts/prepare_network.py
index 27aacacf..2664d362 100755
--- a/scripts/prepare_network.py
+++ b/scripts/prepare_network.py
@@ -257,7 +257,7 @@ if __name__ == "__main__":
         if oo[0].startswith(tuple(suptechs)):
             carrier = oo[0]
             # handles only p_nom_max as stores and lines have no potentials
-            attr_lookup = {"p": "p_nom_max", "c": "capital_cost"}
+            attr_lookup = {"p": "p_nom_max", "c": "capital_cost", "m": "marginal_cost"}
             attr = attr_lookup[oo[1][0]]
             factor = float(oo[1][1:])
             if carrier == "AC":  # lines do not have carrier