diff --git a/Makefile b/Makefile
index 5f93820..4c63532 100644
--- a/Makefile
+++ b/Makefile
@@ -11,7 +11,7 @@ TOOLCHAIN_PREFIX = $(RISCV_GNU_TOOLCHAIN_INSTALL_PREFIX)i/bin/riscv32-unknown-el
 COMPRESSED_ISA = C
 
 test: testbench.vvp firmware/firmware.hex
-	vvp -N testbench.vvp
+	vvp -N $<
 
 test_vcd: testbench.vvp firmware/firmware.hex
 	vvp -N $< +vcd +trace +noerror
@@ -35,29 +35,29 @@ check.smt2: picorv32.v
 		  -p 'write_smt2 -wires check.smt2'
 
 test_sp: testbench_sp.vvp firmware/firmware.hex
-	vvp -N testbench_sp.vvp
+	vvp -N $<
 
 test_axi: testbench.vvp firmware/firmware.hex
-	vvp -N testbench.vvp +axi_test
+	vvp -N $< +axi_test
 
 test_synth: testbench_synth.vvp firmware/firmware.hex
-	vvp -N testbench_synth.vvp
+	vvp -N $<
 
 testbench.vvp: testbench.v picorv32.v
-	iverilog -o testbench.vvp $(subst C,-DCOMPRESSED_ISA,$(COMPRESSED_ISA)) -DRISCV_FORMAL testbench.v picorv32.v
-	chmod -x testbench.vvp
+	iverilog -o $@ $(subst C,-DCOMPRESSED_ISA,$(COMPRESSED_ISA)) -DRISCV_FORMAL $^
+	chmod -x $@
 
 testbench_wb.vvp: testbench_wb.v picorv32.v
 	iverilog -o $@ $(subst C,-DCOMPRESSED_ISA,$(COMPRESSED_ISA)) -DRISCV_FORMAL $^
 	chmod -x $@
 
 testbench_sp.vvp: testbench.v picorv32.v
-	iverilog -o testbench_sp.vvp $(subst C,-DCOMPRESSED_ISA,$(COMPRESSED_ISA)) -DRISCV_FORMAL -DSP_TEST testbench.v picorv32.v
-	chmod -x testbench_sp.vvp
+	iverilog -o $@ $(subst C,-DCOMPRESSED_ISA,$(COMPRESSED_ISA)) -DRISCV_FORMAL -DSP_TEST $^
+	chmod -x $@
 
 testbench_synth.vvp: testbench.v synth.v
-	iverilog -o testbench_synth.vvp -DSYNTH_TEST testbench.v synth.v
-	chmod -x testbench_synth.vvp
+	iverilog -o $@ -DSYNTH_TEST $^
+	chmod -x $@
 
 synth.v: picorv32.v scripts/yosys/synth_sim.ys
 	yosys -qv3 -l synth.log scripts/yosys/synth_sim.ys
diff --git a/testbench.v b/testbench.v
index e113265..9380445 100644
--- a/testbench.v
+++ b/testbench.v
@@ -176,7 +176,7 @@ module picorv32_wrapper #(
 
 	reg [1023:0] firmware_file;
 	initial begin
-		if(!$value$plusargs("firmware=%s", firmware_file))
+		if (!$value$plusargs("firmware=%s", firmware_file))
 			firmware_file = "firmware/firmware.hex";
 		$readmemh(firmware_file, mem.memory);
 	end
@@ -300,7 +300,7 @@ module axi4_memory #(
 	end endtask
 
 	task handle_axi_rvalid; begin
-		if(verbose)
+		if (verbose)
 			$display("RD: ADDR=%08x DATA=%08x%s", latched_raddr, memory[latched_raddr >> 2], latched_rinsn ? " INSN" : "");
 		if (latched_raddr < 64*1024) begin
 			mem_axi_rdata <= memory[latched_raddr >> 2];
diff --git a/testbench_wb.v b/testbench_wb.v
index a613e50..0a1c83f 100644
--- a/testbench_wb.v
+++ b/testbench_wb.v
@@ -294,14 +294,13 @@ module wb_ram #(
 	reg [31:0] mem [0:depth/4-1] /* verilator public */;
 
 	always @(posedge wb_clk_i) begin
-		if (adr_r[aw-1:0] == 32'h1000_0000 && wb_stb_i && !wb_ack_o)
-		begin
-			$write("%c", wb_dat_i[7:0]);
-		end else
-		if (adr_r[aw-1:0] == 32'h2000_0000 && wb_stb_i && !wb_ack_o) begin
-			if (wb_dat_i[31:0] == 123456789)
-				tests_passed = 1;
-		end
+		if (ram_we)
+			if (adr_r[aw-1:0] == 32'h1000_0000)
+				$write("%c", wb_dat_i[7:0]);
+			else
+			if (adr_r[aw-1:0] == 32'h2000_0000)
+				if (wb_dat_i[31:0] == 123456789)
+					tests_passed = 1;
 	end
 
 	always @(posedge wb_clk_i) begin