diff --git a/scripts/cluster_network.py b/scripts/cluster_network.py
index 7572d3b3e..d5d27ef72 100644
--- a/scripts/cluster_network.py
+++ b/scripts/cluster_network.py
@@ -424,7 +424,10 @@ def clustering_for_n_clusters(
             n.links.eval("underwater_fraction * length").div(nc.links.length).dropna()
         )
         nc.links["capital_cost"] = nc.links["capital_cost"].add(
-            (nc.links.length - n.links.length).clip(lower=0).mul(extended_link_costs),
+            (nc.links.length - n.links.length)
+            .clip(lower=0)
+            .mul(extended_link_costs)
+            .dropna(),
             fill_value=0,
         )