diff --git a/.github/workflows/python.yml b/.github/workflows/python.yml
index 3d6ef46b..d8790842 100644
--- a/.github/workflows/python.yml
+++ b/.github/workflows/python.yml
@@ -53,11 +53,11 @@ jobs:
           ;;
         esac
     - name: Install
-      run: pip install -e .
+      run: pip install .
     - name: Run tests
       run: pytest -v
     - name: Tile slide
-      run: python examples/deepzoom/deepzoom_tile.py --viewer -o tiled tests/small.svs
+      run: python examples/deepzoom/deepzoom_tile.py --viewer -o tiled tests/fixtures/small.svs
   windows:
     name: Windows
     needs: pre-commit
@@ -117,7 +117,7 @@ jobs:
         python examples/deepzoom/deepzoom_tile.py -h >/dev/null
     - name: Tile slide
       # Reads OPENSLIDE_PATH
-      run: python examples/deepzoom/deepzoom_tile.py --viewer -o tiled tests/small.svs
+      run: python examples/deepzoom/deepzoom_tile.py --viewer -o tiled tests/fixtures/small.svs
     - name: Archive wheel
       uses: actions/upload-artifact@v3
       with:
diff --git a/.gitignore b/.gitignore
index 78dc7415..87d0e176 100644
--- a/.gitignore
+++ b/.gitignore
@@ -2,5 +2,4 @@
 /dist
 /MANIFEST
 /*.egg-info
-/openslide/_convert*.so
 *.pyc
diff --git a/MANIFEST.in b/MANIFEST.in
index f0efabdd..c0b2779b 100644
--- a/MANIFEST.in
+++ b/MANIFEST.in
@@ -1,4 +1,4 @@
-include *.md
+include *.md pytest.ini
 recursive-include doc *.py *.rst
 recursive-include examples *.html *.js *.png *.py
 recursive-include tests *.png *.py *.svs *.tiff
diff --git a/pytest.ini b/pytest.ini
new file mode 100644
index 00000000..218e0493
--- /dev/null
+++ b/pytest.ini
@@ -0,0 +1,7 @@
+[pytest]
+minversion = 6.0
+# don't try to import openslide from the source directory, since it doesn't
+# have the compiled extension module
+addopts = --import-mode importlib
+# allow tests to import common module
+pythonpath = tests
diff --git a/tests/__init__.py b/tests/common.py
similarity index 97%
rename from tests/__init__.py
rename to tests/common.py
index b65dafdf..1ca8fc25 100644
--- a/tests/__init__.py
+++ b/tests/common.py
@@ -45,7 +45,7 @@
 
 
 def file_path(name):
-    return Path(__file__).parent / name
+    return Path(__file__).parent / 'fixtures' / name
 
 
 def maybe_supported(f):
diff --git a/tests/boxes.png b/tests/fixtures/boxes.png
similarity index 100%
rename from tests/boxes.png
rename to tests/fixtures/boxes.png
diff --git a/tests/boxes.tiff b/tests/fixtures/boxes.tiff
similarity index 100%
rename from tests/boxes.tiff
rename to tests/fixtures/boxes.tiff
diff --git a/tests/small.svs b/tests/fixtures/small.svs
similarity index 100%
rename from tests/small.svs
rename to tests/fixtures/small.svs
diff --git a/tests/unopenable.tiff b/tests/fixtures/unopenable.tiff
similarity index 100%
rename from tests/unopenable.tiff
rename to tests/fixtures/unopenable.tiff
diff --git a/tests/unreadable.svs b/tests/fixtures/unreadable.svs
similarity index 100%
rename from tests/unreadable.svs
rename to tests/fixtures/unreadable.svs
diff --git a/tests/test_base.py b/tests/test_base.py
index dc961625..1ffc186f 100644
--- a/tests/test_base.py
+++ b/tests/test_base.py
@@ -19,9 +19,9 @@
 
 import unittest
 
-from openslide import ImageSlide, OpenSlide, open_slide
+from common import file_path
 
-from . import file_path
+from openslide import ImageSlide, OpenSlide, open_slide
 
 
 class TestLibrary(unittest.TestCase):
diff --git a/tests/test_deepzoom.py b/tests/test_deepzoom.py
index 332cf0a4..892d9d04 100644
--- a/tests/test_deepzoom.py
+++ b/tests/test_deepzoom.py
@@ -19,11 +19,11 @@
 
 import unittest
 
+from common import file_path
+
 from openslide import ImageSlide, OpenSlide
 from openslide.deepzoom import DeepZoomGenerator
 
-from . import file_path
-
 
 class _BoxesDeepZoomTest:
     def setUp(self):
diff --git a/tests/test_imageslide.py b/tests/test_imageslide.py
index 64540dc5..d3a22977 100644
--- a/tests/test_imageslide.py
+++ b/tests/test_imageslide.py
@@ -20,11 +20,10 @@
 import unittest
 
 from PIL import Image
+from common import file_path, maybe_supported
 
 from openslide import ImageSlide, OpenSlideCache, OpenSlideError
 
-from . import file_path, maybe_supported
-
 
 class TestImageWithoutOpening(unittest.TestCase):
     def test_detect_format(self):
diff --git a/tests/test_openslide.py b/tests/test_openslide.py
index 62de390a..52bffdd2 100644
--- a/tests/test_openslide.py
+++ b/tests/test_openslide.py
@@ -23,6 +23,7 @@
 import unittest
 
 from PIL import Image
+from common import file_path, maybe_supported
 
 from openslide import (
     OpenSlide,
@@ -31,8 +32,6 @@
     OpenSlideUnsupportedFormatError,
 )
 
-from . import file_path, maybe_supported
-
 
 class TestCache(unittest.TestCase):
     @maybe_supported