diff --git a/scripts/simplify_network.py b/scripts/simplify_network.py
index 4e573ebac..b3f4b4e01 100644
--- a/scripts/simplify_network.py
+++ b/scripts/simplify_network.py
@@ -269,6 +269,8 @@ def simplify_links(n, costs, config, output, aggregation_strategies=dict()):
     logger.info("Simplifying connected link components")
 
     if n.links.empty:
+        with open(output.connection_costs, "w") as fp:
+            pass
         return n, n.buses.index.to_series()
 
     # Determine connected link components, ignore all links but DC