diff --git a/Lib/test/test_ossaudiodev.py b/Lib/test/test_ossaudiodev.py
index 9f64406..d2f63ae 100644
--- a/Lib/test/test_ossaudiodev.py
+++ b/Lib/test/test_ossaudiodev.py
@@ -40,6 +40,10 @@
     data = audioop.ulaw2lin(data, 2)
     return (data, rate, 16, nchannels)
 
+# version of assert that still works with -O
+def _assert(expr, message=None):
+    if not expr:
+        raise AssertionError(message or "assertion failed")
 
 def play_sound_file(data, rate, ssize, nchannels):
     try:
@@ -57,9 +61,9 @@
     dsp.fileno()
 
     # Make sure the read-only attributes work.
-    assert dsp.closed is False, "dsp.closed is not False"
-    assert dsp.name == "/dev/dsp"
-    assert dsp.mode == 'w', "bad dsp.mode: %r" % dsp.mode
+    _assert(dsp.closed is False, "dsp.closed is not False")
+    _assert(dsp.name == "/dev/dsp")
+    _assert(dsp.mode == 'w', "bad dsp.mode: %r" % dsp.mode)
 
     # And make sure they're really read-only.
     for attr in ('closed', 'name', 'mode'):
@@ -83,11 +87,9 @@
     elapsed_time = t2 - t1
 
     percent_diff = (abs(elapsed_time - expected_time) / expected_time) * 100
-    #print ("actual running time was %.2f sec (%.1f%% difference)"
-    #       % (elapsed_time, percent_diff))
-    assert percent_diff <= 10.0, \
-           ("elapsed time (%.2f sec) > 10%% off of expected time (%.2f sec)"
-            % (elapsed_time, expected_time))
+    _assert(percent_diff <= 10.0, \
+            ("elapsed time (%.2f sec) > 10%% off of expected time (%.2f sec)"
+             % (elapsed_time, expected_time)))
 
 def test_setparameters(dsp):
     # Two configurations for testing:
@@ -112,11 +114,11 @@
     # setparameters() should be able to set this configuration in
     # either strict or non-strict mode.
     result = dsp.setparameters(fmt, channels, rate, False)
-    assert result == (fmt, channels, rate), \
-           "setparameters%r: returned %r" % (config + result)
+    _assert(result == (fmt, channels, rate),
+            "setparameters%r: returned %r" % (config + result))
     result = dsp.setparameters(fmt, channels, rate, True)
-    assert result == (fmt, channels, rate), \
-           "setparameters%r: returned %r" % (config + result)
+    _assert(result == (fmt, channels, rate),
+            "setparameters%r: returned %r" % (config + result))
 
 def test_bad_setparameters(dsp):
 
@@ -134,8 +136,8 @@
                   ]:
         (fmt, channels, rate) = config
         result = dsp.setparameters(fmt, channels, rate, False)
-        assert result != config, \
-               "setparameters: unexpectedly got requested configuration"
+        _assert(result != config,
+                "setparameters: unexpectedly got requested configuration")
 
         try:
             result = dsp.setparameters(fmt, channels, rate, True)
@@ -156,6 +158,6 @@
         #test_bad_setparameters(dsp)
     finally:
         dsp.close()
-        assert dsp.closed is True, "dsp.closed is not True"
+        _assert(dsp.closed is True, "dsp.closed is not True")
 
 test()