diff --git a/Tests/test_file_avif.py b/Tests/test_file_avif.py
index 727191153..5ada98bda 100644
--- a/Tests/test_file_avif.py
+++ b/Tests/test_file_avif.py
@@ -772,6 +772,7 @@ class TestAvifAnimation:
 MAX_THREADS = os.cpu_count() or 1
 
 
+@pytest.mark.xdist_group(name="leak-group")
 @skip_unless_feature("avif")
 class TestAvifLeaks(PillowLeakTestCase):
     mem_limit = MAX_THREADS * 3 * 1024
diff --git a/pyproject.toml b/pyproject.toml
index db2474752..2f63f756b 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -209,7 +209,7 @@ lint.isort.required-imports = [
 max_supported_python = "3.14"
 
 [tool.pytest.ini_options]
-addopts = "-ra --color=auto --numprocesses=auto"
+addopts = "-ra --color=auto --numprocesses=auto --dist=loadgroup"
 testpaths = [
   "Tests",
 ]