diff --git a/README.md b/README.md
index 189e48161..728f64bca 100644
--- a/README.md
+++ b/README.md
@@ -149,8 +149,9 @@ software libraries, which we ship in several different ways:
      use can use either hardware-accelerated rendering via EGL or GLX or
      software rendering via OSMesa, depending on the `--define headless=...`
      build setting.
-   * Python 2.7 (other versions might work, too) with NumPy and PIL. (A few
-     tests require a NumPy version of at least 1.8.)
+   * Python 2.7 (other versions might work, too) with NumPy, PIL. (A few
+     tests require a NumPy version of at least 1.8.) One test requires six
+     to demonstrate Python 3 compatibility.
 
 The build rules are using a few compiler settings that are specific to GCC. If
 some flags are not recognized by your compiler (typically those would be
diff --git a/docs/users/python_api.md b/docs/users/python_api.md
index 14f0adcb3..f65c49c7f 100644
--- a/docs/users/python_api.md
+++ b/docs/users/python_api.md
@@ -8,6 +8,12 @@ usage, there is
 [python/random_agent.py](../../python/random_agent.py), and
 [python/random_agent_simple.py](../../python/random_agent_simple.py).
 
+**A note about Python 3:** By and large the Python API requires Python 2.7.
+However, there is experimental support for Python 3. Under Python 3, strings
+coming out of the environment (e.g. event names or string observations) have to
+be valid UTF-8. The `dmlab_module_test.py` demonstrates how to write code that
+works both in Python 2.7 and Python 3 (using the `six` package).
+
 ### class `deepmind_lab.Lab`(*level*, *observations*, *config={}*, *renderer='software'*)
 
 Creates an environment object, loading the game script file *level*. The
diff --git a/python/tests/dmlab_module_test.py b/python/tests/dmlab_module_test.py
index 7fcbba3c8..835cd545a 100644
--- a/python/tests/dmlab_module_test.py
+++ b/python/tests/dmlab_module_test.py
@@ -22,6 +22,7 @@
 import os
 import unittest
 import numpy as np
+import six
 
 import deepmind_lab
 
@@ -31,7 +32,7 @@ class DeepMindLabTest(unittest.TestCase):
   def testInitArgs(self):
     with self.assertRaisesRegexp(TypeError, 'must be dict, not list'):
       deepmind_lab.Lab('tests/empty_room_test', [], ['wrongconfig'])
-    with self.assertRaisesRegexp(TypeError, 'str'):
+    with self.assertRaisesRegexp(TypeError, 'str|bad argument type'):
       deepmind_lab.Lab('tests/empty_room_test', [], {'wrongtype': 3})
     with self.assertRaisesRegexp(TypeError, 'must be list, not None'):
       deepmind_lab.Lab('tests/empty_room_test', None, {})
@@ -83,7 +84,7 @@ def testRun(self, steps=10, observation='RGB_INTERLACED'):
     env = deepmind_lab.Lab('lt_chasm', [observation])
     env.reset()
 
-    for _ in xrange(steps):
+    for _ in six.moves.range(steps):
       obs = env.observations()
       action = np.zeros((7,), dtype=np.intc)
       reward = env.step(action, num_steps=4)
@@ -107,26 +108,25 @@ def testRunfilesPath(self):
     self.assertTrue(os.stat(deepmind_lab.runfiles_path()))
 
   def testWidthHeight(self, width=80, height=80, steps=10, num_steps=1):
-    observations = ['RGBD']
-    env = deepmind_lab.Lab('lt_chasm', observations,
-                           config={'height': str(height),
-                                   'width': str(width)})
+    observation = 'RGBD'
+    env = deepmind_lab.Lab(
+        'lt_chasm', [observation],
+        config={'height': str(height), 'width': str(width)})
     env.reset()
 
-    for _ in xrange(steps):
+    for _ in six.moves.range(steps):
       obs = env.observations()
       action = np.zeros((7,), dtype=np.intc)
       reward = env.step(action, num_steps=num_steps)
 
-      self.assertEqual(obs[observations[0]].shape, (4, width, height))
+      self.assertEqual(obs[observation].shape, (4, width, height))
       self.assertEqual(reward, 0.0)
 
   def testStringObervations(self):
     observation = 'CUSTOM_TEXT'
     env = deepmind_lab.Lab(
         'tests/text_observation_test', [observation],
-        config={'height': str(32),
-                'width': str(32)})
+        config={'height': '32', 'width': '32'})
     observation_spec = env.observation_spec()
     observation_spec_lookup = {o['name']: o for o in observation_spec}
     spec = observation_spec_lookup[observation]
@@ -138,8 +138,8 @@ def testStringObervations(self):
 
   def testEvents(self):
     env = deepmind_lab.Lab(
-        'tests/event_test', [], config={'height': str(32),
-                                              'width': str(32)})
+        'tests/event_test', [],
+        config={'height': '32', 'width': '32'})
     env.reset(episode=1, seed=7)
     events = env.events()
     self.assertEqual(len(events), 4)
@@ -191,17 +191,16 @@ def testVeloctyObservations(self, width=80, height=80):
     backward_action = - forward_action
     look_sideways_action = np.array([512, 0, 0, 0, 0, 0, 0], dtype=np.intc)
 
-    env = deepmind_lab.Lab('seekavoid_arena_01', ['VEL.TRANS', 'VEL.ROT'],
-                           config={'height': str(height),
-                                   'width': str(width),
-                                   'fps': '60'})
+    env = deepmind_lab.Lab(
+        'seekavoid_arena_01', ['VEL.TRANS', 'VEL.ROT'],
+        config={'height': str(height), 'width': str(width), 'fps': '60'})
 
     env.reset(seed=1)
 
     # Initial landing on the ground.
     env.step(noop_action, num_steps=180)
 
-    for _ in xrange(3):
+    for _ in six.moves.range(3):
       # Doing nothing should result in velocity observations of zero.
       env.step(noop_action, num_steps=100)
       obs = env.observations()
@@ -227,7 +226,7 @@ def testVeloctyObservations(self, width=80, height=80):
 
     env.reset(seed=1)
 
-    for _ in xrange(3):
+    for _ in six.moves.range(3):
       env.step(noop_action, num_steps=100)
       obs = env.observations()
       np.testing.assert_array_equal(obs['VEL.TRANS'], np.zeros((3,)))