diff --git a/Overlap/eddy_graph_in.sh b/Overlap/eddy_graph_in.sh
index 078b531ea68f9e1ae87258608ae44b1375f04571..eb46ba94501e053a4fc1426d9c32f59b1028ab89 100755
--- a/Overlap/eddy_graph_in.sh
+++ b/Overlap/eddy_graph_in.sh
@@ -26,7 +26,8 @@ done
 
 # Sort the edge list for easier comparison between runs:
 export LC_NUMERIC=C # for the sort command
-sort --key=1,1 --numeric-sort --output=edgelist.csv edgelist_unsorted.csv
+sort --key=1,1 --key=2,2 --numeric-sort --output=edgelist.csv \
+     edgelist_unsorted.csv
 rm edgelist_unsorted.csv
 
 echo "Created files \"edgelist.csv\", \"isolated_nodes.txt\" and " \