diff --git a/scripts/simplify_network.py b/scripts/simplify_network.py
index 2db5c7136..89a05af3f 100644
--- a/scripts/simplify_network.py
+++ b/scripts/simplify_network.py
@@ -471,7 +471,8 @@ def aggregate_to_substations(n, aggregation_strategies=dict(), buses_i=None):
         dist.loc[incarrier_b, ~incarrier_b] = np.inf
 
     busmap = n.buses.index.to_series()
-    busmap.loc[buses_i] = dist.idxmin(1)
+    if dist:
+        busmap.loc[buses_i] = dist.idxmin(1)
 
     bus_strategies, generator_strategies = get_aggregation_strategies(
         aggregation_strategies