diff --git a/tests/conftest.py b/tests/conftest.py
index d9dfebea..d3b86061 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -44,7 +44,7 @@ TESTS_ROOT = Path(__file__).parent.resolve()
 PROJECT_ROOT = TESTS_ROOT
 
 
-@pytest.fixture
+@pytest.fixture(scope="session")
 def resources() -> Path:
     return Path(TESTS_ROOT) / 'resources'
 
@@ -78,6 +78,11 @@ def no_outpdf(tmp_path) -> Path:
     return tmp_path / 'no_output.pdf'
 
 
+@pytest.fixture(scope="session")
+def multipage(resources):
+    return resources / 'multipage.pdf'
+
+
 def check_ocrmypdf(input_file: Path, output_file: Path, *args) -> Path:
     """Run ocrmypdf and confirm that a valid plausible PDF was created."""
     api_args = [str(input_file), str(output_file)] + [
diff --git a/tests/test_concurrency.py b/tests/test_concurrency.py
index e5244ddb..4e600bc3 100644
--- a/tests/test_concurrency.py
+++ b/tests/test_concurrency.py
@@ -14,9 +14,9 @@ from .conftest import run_ocrmypdf_api
 
 @pytest.mark.skipif(True, reason="--use-threads is currently default")
 @pytest.mark.skipif(os.name == 'nt', reason="Windows doesn't have SIGKILL")
-def test_simulate_oom_killer(resources, no_outpdf):
+def test_simulate_oom_killer(multipage, no_outpdf):
     exitcode = run_ocrmypdf_api(
-        resources / 'multipage.pdf',
+        multipage,
         no_outpdf,
         '--force-ocr',
         '--plugin',
diff --git a/tests/test_main.py b/tests/test_main.py
index 06d0b363..676c17cb 100644
--- a/tests/test_main.py
+++ b/tests/test_main.py
@@ -7,11 +7,10 @@ import os
 import shutil
 from math import isclose
 from pathlib import Path
-from subprocess import PIPE, run
+from subprocess import run
 from unittest.mock import patch
 
 import pikepdf
-import PIL
 import pytest
 from PIL import Image
 
@@ -153,9 +152,9 @@ def test_skip_big(resources, outpdf):
 
 @pytest.mark.parametrize('renderer', RENDERERS)
 @pytest.mark.parametrize('output_type', ['pdf', 'pdfa'])
-def test_maximum_options(renderer, output_type, resources, outpdf):
+def test_maximum_options(renderer, output_type, multipage, outpdf):
     check_ocrmypdf(
-        resources / 'multipage.pdf',
+        multipage,
         outpdf,
         '-d',
         '-ci' if have_unpaper() else None,
diff --git a/tests/test_optimize.py b/tests/test_optimize.py
index 9c63a41d..5717269e 100644
--- a/tests/test_optimize.py
+++ b/tests/test_optimize.py
@@ -27,10 +27,15 @@ needs_jbig2enc = pytest.mark.skipif(
 )
 
 
+@pytest.fixture(scope="session")
+def palette(resources):
+    return resources / 'palette.pdf'
+
+
 @needs_pngquant
-@pytest.mark.parametrize('pdf', ['multipage.pdf', 'palette.pdf'])
-def test_basic(resources, pdf, outpdf):
-    infile = resources / pdf
+@pytest.mark.parametrize('pdf', ['multipage', 'palette'])
+def test_basic(multipage, palette, pdf, outpdf):
+    infile = multipage if pdf == 'multipage' else palette
     opt.main(infile, outpdf, level=3)
 
     assert 0.98 * Path(outpdf).stat().st_size <= Path(infile).stat().st_size
diff --git a/tests/test_page_numbers.py b/tests/test_page_numbers.py
index a04dbb53..aac80c0d 100644
--- a/tests/test_page_numbers.py
+++ b/tests/test_page_numbers.py
@@ -48,10 +48,9 @@ def test_nonmonotonic_warning(caplog):
     assert 'out of order' in caplog.text
 
 
-def test_limited_pages(resources, outpdf):
-    multi = resources / 'multipage.pdf'
+def test_limited_pages(multipage, outpdf):
     ocrmypdf.ocr(
-        multi,
+        multipage,
         outpdf,
         pages='5-6',
         optimize=0,