diff --git a/scripts/process_subways.sh b/scripts/process_subways.sh
index 91dfada..fcc46d4 100755
--- a/scripts/process_subways.sh
+++ b/scripts/process_subways.sh
@@ -66,7 +66,7 @@ PLANET_ABS="$(cd "$(dirname "$PLANET")"; pwd)/$(basename "$PLANET")"
 FILTERED_DATA="$TMPDIR/subways.osm"
 QRELATIONS="route=subway =light_rail =monorail =train route_master=subway =light_rail =monorail =train public_transport=stop_area =stop_area_group"
 QNODES="railway=station station=subway =light_rail =monorail railway=subway_entrance subway=yes light_rail=yes monorail=yes train=yes"
-"$OSMCTOOLS/osmfilter" "$PLANET" --keep= --keep-relations="$QRELATIONS" --keep-nodes="$QNODES" --drop-author "-o=$FILTERED_DATA"
+"$OSMCTOOLS/osmfilter" "$PLANET" --keep= --keep-relations="$QRELATIONS" --keep-nodes="$QNODES" --drop-author -o="$FILTERED_DATA"
 
 # Running the validation