diff --git a/ice40/picorv32_arachne.sh b/ice40/picorv32_arachne.sh
index 285562c1..e166487a 100755
--- a/ice40/picorv32_arachne.sh
+++ b/ice40/picorv32_arachne.sh
@@ -4,6 +4,6 @@ rm -f picorv32.v
 wget https://raw.githubusercontent.com/cliffordwolf/picorv32/master/picorv32.v
 yosys -p 'synth_ice40 -nocarry -blif picorv32.blif -top top' picorv32.v picorv32_top.v
 arachne-pnr -d 8k --post-place-blif picorv32_place.blif picorv32.blif
-yosys picorv32_place.blif -o picorv32_place.json
+yosys picorv32_place.blif -p "read_verilog -lib +/ice40/cells_sim.v; write_json picorv32_place.json"
 ./transform_arachne_loc.py picorv32_place.json > picorv32_place_nx.json
 ../nextpnr-ice40 --hx8k --asc picorv32.asc --json picorv32_place_nx.json