diff --git a/ml-proto/runtests.py b/ml-proto/runtests.py
index 1a0bb389cd..6e9fafcdd4 100755
--- a/ml-proto/runtests.py
+++ b/ml-proto/runtests.py
@@ -1,34 +1,70 @@
 #!/usr/bin/env python
 
+import os
 import os.path
 import unittest
 import subprocess
 import glob
+import sys
 
 class RunTests(unittest.TestCase):
   def _runTestFile(self, shortName, fileName, interpreterPath):
     print("\n// %s" % shortName)
-    exitCode = subprocess.call([interpreterPath, fileName])
+    sys.stdout.flush()
+
+    logPath = fileName.replace("test/", "test/output/").replace(".wasm", ".wasm.log")
+    try:
+      os.remove(logPath)
+    except OSError:
+      pass
+
+    commandStr = ("%s %s | tee %s") % (interpreterPath, fileName, logPath)
+    exitCode = subprocess.call(commandStr, shell=True)
     self.assertEqual(0, exitCode, "test runner failed with exit code %i" % exitCode)
 
+    try:
+      expected = open(fileName.replace("test/", "test/expected-output/").replace(".wasm", ".wasm.log"))
+    except IOError:
+      print("// WARNING: No expected output found for this test")
+      return
+
+    output = open(logPath)
+
+    with expected:
+      with output:
+        expectedText = expected.read()
+        actualText = output.read()
+        self.assertEqual(expectedText, actualText)
+
+def generate_test_case(rec):
+  return lambda self : self._runTestFile(*rec)
+
+
 def generate_test_cases(cls, interpreterPath, files):
   for fileName in files:
-    absFileName = os.path.abspath(fileName)
     attrName = fileName
-    testCase = lambda self : self._runTestFile(attrName, absFileName, interpreterPath)
+    rec = (attrName, fileName, interpreterPath)
+    testCase = generate_test_case(rec)
     setattr(cls, attrName, testCase)
 
 def rebuild_interpreter():
   interpreterPath = os.path.abspath("src/main.native")
 
   print("// building main.native")
+  sys.stdout.flush()
   exitCode = subprocess.call(["ocamlbuild", "-libs", "bigarray", "main.native"], cwd=os.path.abspath("src"))
   if (exitCode != 0):
     raise Exception("ocamlbuild failed with exit code %i" % exitCode)
 
   return interpreterPath
 
-if __name__ == "__main__":  
+if __name__ == "__main__":
+  try:
+    os.makedirs("test/output/")
+  except OSError:
+    pass
+
   interpreterPath = rebuild_interpreter()
-  generate_test_cases(RunTests, interpreterPath, glob.glob("test/*.wasm"))
+  testFiles = glob.glob("test/*.wasm")
+  generate_test_cases(RunTests, interpreterPath, testFiles)
   unittest.main()
\ No newline at end of file
diff --git a/ml-proto/test/.gitignore b/ml-proto/test/.gitignore
new file mode 100644
index 0000000000..6caf68aff4
--- /dev/null
+++ b/ml-proto/test/.gitignore
@@ -0,0 +1 @@
+output
\ No newline at end of file
diff --git a/ml-proto/test/expected-output/fac.wasm.log b/ml-proto/test/expected-output/fac.wasm.log
new file mode 100644
index 0000000000..e0b0cad50a
--- /dev/null
+++ b/ml-proto/test/expected-output/fac.wasm.log
@@ -0,0 +1,4 @@
+export 0 : i64 -> i64
+export 1 : i64 -> i64
+7034535277573963776 : i64
+7034535277573963776 : i64
diff --git a/ml-proto/test/expected-output/memory.wasm.log b/ml-proto/test/expected-output/memory.wasm.log
new file mode 100644
index 0000000000..92d718b11b
--- /dev/null
+++ b/ml-proto/test/expected-output/memory.wasm.log
@@ -0,0 +1,8 @@
+export 0 : () -> i32
+export 1 : () -> i32
+export 2 : () -> i32
+export 3 : () -> f64
+1 : i32
+1 : i32
+1 : i32
+-3.10552331246e+231 : f64