diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index cb972de..28d0a13 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -93,3 +93,17 @@ jobs:
     steps:
     - uses: actions/checkout@v2
     - run: make DOCKER=1 microwatt.v
+
+  verilator:
+    runs-on: ubuntu-latest
+    env:
+      DOCKER: 1
+      FPGA_TARGET: verilator
+      RAM_INIT_FILE: micropython/firmware.hex
+      MEMORY_SIZE: 524288
+    steps:
+    - uses: actions/checkout@v2
+    - run: |
+        sudo apt update
+        sudo apt install -y python3-pexpect
+        make -j$(nproc) test_micropython_verilator test_micropython_verilator_long
diff --git a/Makefile b/Makefile
index a4b8df5..9f308ba 100644
--- a/Makefile
+++ b/Makefile
@@ -1,7 +1,8 @@
 GHDL ?= ghdl
 GHDLFLAGS=--std=08
 CFLAGS=-O3 -Wall
-VERILATOR_FLAGS=-O3 #--trace
+# Need to investigate why yosys is hitting verilator warnings, and eventually turn on -Wall
+VERILATOR_FLAGS=-O3 -Wno-fatal -Wno-CASEOVERLAP -Wno-UNOPTFLAT #--trace
 # It takes forever to build with optimisation, so disable by default
 #VERILATOR_CFLAGS=-O3
 
@@ -11,6 +12,7 @@ NEXTPNR   ?= nextpnr-ecp5
 ECPPACK   ?= ecppack
 OPENOCD   ?= openocd
 VUNITRUN  ?= python3 ./run.py
+VERILATOR ?= verilator
 
 # We need a version of GHDL built with either the LLVM or gcc backend.
 # Fedora provides this, but other distros may not. Another option is to use
@@ -39,6 +41,7 @@ NEXTPNR   = $(DOCKERBIN) $(DOCKERARGS) hdlc/nextpnr:ecp5 nextpnr-ecp5
 ECPPACK   = $(DOCKERBIN) $(DOCKERARGS) hdlc/prjtrellis ecppack
 OPENOCD   = $(DOCKERBIN) $(DOCKERARGS) --device /dev/bus/usb hdlc/prog openocd
 VUNITRUN  = $(DOCKERBIN) $(DOCKERARGS) ghdl/vunit:llvm python3 ./run.py
+VERILATOR = $(DOCKERBIN) $(DOCKERARGS) verilator/verilator:latest
 endif
 
 VUNITARGS += -p10
@@ -138,8 +141,8 @@ $(soc_dram_tbs): %: $(soc_dram_files) $(soc_dram_sim_files) $(soc_dram_sim_obj_f
 endif
 
 # Hello world
-MEMORY_SIZE=8192
-RAM_INIT_FILE=hello_world/hello_world.hex
+MEMORY_SIZE ?=8192
+RAM_INIT_FILE ?=hello_world/hello_world.hex
 
 # Micropython
 #MEMORY_SIZE=393216
@@ -201,10 +204,8 @@ microwatt.json: $(synth_files) $(RAM_INIT_FILE)
 microwatt.v: $(synth_files) $(RAM_INIT_FILE)
 	$(YOSYS) -m $(GHDLSYNTH) -p "ghdl --std=08 --no-formal $(GHDL_IMAGE_GENERICS) $(synth_files) -e toplevel; write_verilog $@"
 
-# Need to investigate why yosys is hitting verilator warnings, and eventually turn on -Wall
 microwatt-verilator: microwatt.v verilator/microwatt-verilator.cpp verilator/uart-verilator.c
-	verilator $(VERILATOR_FLAGS) -CFLAGS "$(VERILATOR_CFLAGS) -DCLK_FREQUENCY=$(CLK_FREQUENCY)" --assert --cc $< --exe verilator/microwatt-verilator.cpp verilator/uart-verilator.c -o $@ -Iuart16550 -Wno-fatal -Wno-CASEOVERLAP -Wno-UNOPTFLAT
-	make -C obj_dir -f Vmicrowatt.mk
+	$(VERILATOR) $(VERILATOR_FLAGS) -CFLAGS "$(VERILATOR_CFLAGS) -DCLK_FREQUENCY=$(CLK_FREQUENCY)" -Iuart16550 --assert --cc --exe --build $^ -o $@ -top-module toplevel
 	@cp -f obj_dir/microwatt-verilator microwatt-verilator
 
 microwatt_out.config: microwatt.json $(LPF)
@@ -240,9 +241,15 @@ $(tests_console): core_tb
 test_micropython: core_tb
 	@./scripts/test_micropython.py
 
+test_micropython_verilator: microwatt-verilator
+	@./scripts/test_micropython_verilator.py
+
 test_micropython_long: core_tb
 	@./scripts/test_micropython_long.py
 
+test_micropython_verilator_long: microwatt-verilator
+	@./scripts/test_micropython_verilator_long.py
+
 tests_soc_tb = $(patsubst %_tb,%_tb_test,$(soc_tbs))
 
 %_test: %
diff --git a/scripts/test_micropython_verilator.py b/scripts/test_micropython_verilator.py
new file mode 100755
index 0000000..fe94d52
--- /dev/null
+++ b/scripts/test_micropython_verilator.py
@@ -0,0 +1,31 @@
+#!/usr/bin/python3
+
+import os
+import subprocess
+from pexpect import fdpexpect
+import sys
+import signal
+
+cmd = [ './microwatt-verilator' ]
+
+devNull = open(os.devnull, 'w')
+p = subprocess.Popen(cmd, stdout=subprocess.PIPE,
+        stdin=subprocess.PIPE, stderr=devNull)
+
+exp = fdpexpect.fdspawn(p.stdout)
+exp.logfile = sys.stdout.buffer
+
+exp.expect('Type "help\(\)" for more information.')
+exp.expect('>>>')
+
+p.stdin.write(b'print("foo")\r\n')
+p.stdin.flush()
+
+# Catch the command echoed back to the console
+exp.expect('foo', timeout=600)
+
+# Now catch the output
+exp.expect('foo', timeout=600)
+exp.expect('>>>')
+
+os.kill(p.pid, signal.SIGKILL)
diff --git a/scripts/test_micropython_verilator_long.py b/scripts/test_micropython_verilator_long.py
new file mode 100755
index 0000000..36175f9
--- /dev/null
+++ b/scripts/test_micropython_verilator_long.py
@@ -0,0 +1,39 @@
+#!/usr/bin/python3
+
+import os
+import subprocess
+from pexpect import fdpexpect
+import sys
+import signal
+
+cmd = [ './microwatt-verilator' ]
+
+devNull = open(os.devnull, 'w')
+p = subprocess.Popen(cmd, stdout=subprocess.PIPE,
+        stdin=subprocess.PIPE, stderr=devNull)
+
+exp = fdpexpect.fdspawn(p.stdout)
+exp.logfile = sys.stdout.buffer
+
+exp.expect('Type "help\(\)" for more information.')
+exp.expect('>>>')
+
+p.stdin.write(b'n2=0\r\n')
+p.stdin.write(b'n1=1\r\n')
+p.stdin.write(b'for i in range(5):\r\n')
+p.stdin.write(b'    n0 = n1 + n2\r\n')
+p.stdin.write(b'    print(n0)\r\n')
+p.stdin.write(b'    n2 = n1\r\n')
+p.stdin.write(b'    n1 = n0\r\n')
+p.stdin.write(b'\r\n')
+p.stdin.flush()
+
+exp.expect('n1 = n0', timeout=600)
+exp.expect('1', timeout=600)
+exp.expect('2', timeout=600)
+exp.expect('3', timeout=600)
+exp.expect('5', timeout=600)
+exp.expect('8', timeout=600)
+exp.expect('>>>', timeout=600)
+
+os.kill(p.pid, signal.SIGKILL)
diff --git a/verilator/microwatt-verilator.cpp b/verilator/microwatt-verilator.cpp
index 1e82820..3c37f0a 100644
--- a/verilator/microwatt-verilator.cpp
+++ b/verilator/microwatt-verilator.cpp
@@ -1,5 +1,5 @@
 #include <stdlib.h>
-#include "Vmicrowatt.h"
+#include "Vtoplevel.h"
 #include "verilated.h"
 #include "verilated_vcd_c.h"
 
@@ -24,7 +24,7 @@ double sc_time_stamp(void)
 VerilatedVcdC *tfp;
 #endif
 
-void tick(Vmicrowatt *top)
+void tick(Vtoplevel *top)
 {
 	top->ext_clk = 1;
 	top->eval();
@@ -51,7 +51,7 @@ int main(int argc, char **argv)
 	Verilated::commandArgs(argc, argv);
 
 	// init top verilog instance
-	Vmicrowatt* top = new Vmicrowatt;
+	Vtoplevel* top = new Vtoplevel;
 
 #if VM_TRACE
 	// init trace dump