diff --git a/html5lib/tests/test_encoding.py b/html5lib/tests/test_encoding.py
index 3837fe09..41b888c4 100644
--- a/html5lib/tests/test_encoding.py
+++ b/html5lib/tests/test_encoding.py
@@ -8,7 +8,7 @@
 except AttributeError:
     unittest.TestCase.assertEqual = unittest.TestCase.assertEquals
 
-from .support import get_data_files, TestData, test_dir, errorMessage
+from .support import get_data_files, test_dir, errorMessage, TestData as _TestData
 from html5lib import HTMLParser, inputstream
 
 
@@ -56,7 +56,7 @@ def runPreScanEncodingTest(data, encoding):
 
 def test_encoding():
     for filename in get_data_files("encoding"):
-        tests = TestData(filename, b"data", encoding=None)
+        tests = _TestData(filename, b"data", encoding=None)
         for idx, test in enumerate(tests):
             yield (runParserEncodingTest, test[b'data'], test[b'encoding'])
             yield (runPreScanEncodingTest, test[b'data'], test[b'encoding'])
diff --git a/pytest.ini b/pytest.ini
index 6875cc7d..8824977a 100644
--- a/pytest.ini
+++ b/pytest.ini
@@ -1,2 +1,17 @@
 [pytest]
-addopts = -rXw -p no:doctest
+# Output fails, errors, xpass, and warnings; ignore doctest; make warnings errors
+addopts = -rfEXw -p no:doctest --strict
+
+# Make xpass results be considered fail
+xfail_strict = true
+
+# Document our markers
+markers =
+    DOM: mark a test as a DOM tree test
+    ElementTree: mark a test as a ElementTree tree test
+    cElementTree: mark a test as a cElementTree tree test
+    lxml: mark a test as a lxml tree test
+    genshi: mark a test as a genshi tree test
+    parser: mark a test as a parser test
+    namespaced: mark a test as a namespaced parser test
+    treewalker: mark a test as a treewalker test