diff --git a/scripts/prepare_sector_network.py b/scripts/prepare_sector_network.py
index 5abd2ce6..8eb38d69 100755
--- a/scripts/prepare_sector_network.py
+++ b/scripts/prepare_sector_network.py
@@ -3536,8 +3536,8 @@ def lossy_bidirectional_links(n, carrier, efficiencies={}):
     rev_links["reversed"] = True
     rev_links.index = rev_links.index.map(lambda x: x + "-reversed")
 
-    n.links["reversed"] = False
     n.links = pd.concat([n.links, rev_links], sort=False)
+    n.links["reversed"] = n.links["reversed"].fillna(False)
     n.links["length_original"] = n.links["length_original"].fillna(n.links.length)
 
     # do compression losses after concatenation to take electricity consumption at bus0 in either direction