diff --git a/picosoc/Makefile b/picosoc/Makefile
index 39e3982..88d3014 100644
--- a/picosoc/Makefile
+++ b/picosoc/Makefile
@@ -11,7 +11,7 @@ hx8kdemo.blif: hx8kdemo.v spimemio.v simpleuart.v picosoc.v ../picorv32.v
 	yosys -ql hx8kdemo.log -p 'synth_ice40 -top hx8kdemo -blif hx8kdemo.blif' $^
 
 hx8kdemo_tb.vvp: hx8kdemo_tb.v hx8kdemo.v spimemio.v simpleuart.v picosoc.v ../picorv32.v spiflash.v
-	iverilog -s testbench -o $@ -D DEBUGREGS $^ `yosys-config --datdir/ice40/cells_sim.v`
+	iverilog -s testbench -o $@ $^ `yosys-config --datdir/ice40/cells_sim.v`
 
 hx8kdemo_syn_tb.vvp: hx8kdemo_tb.v hx8kdemo_syn.v spiflash.v
 	iverilog -s testbench -o $@ $^ `yosys-config --datdir/ice40/cells_sim.v`