diff --git a/Makefile b/Makefile
index 3a94b3c..62c3d6b 100644
--- a/Makefile
+++ b/Makefile
@@ -47,7 +47,7 @@ lint:             ## Run pep8, black, mypy linters.
 
 .PHONY: test
 test:             ## Run tests and generate coverage report.
-	$(ENV_PREFIX)pytest -vv -s --cov-config .coveragerc --cov=tosfs -l --tb=short --maxfail=1 tosfs/tests/ --ignore=tosfs/tests/test_stability.py
+	$(ENV_PREFIX)pytest -vv -s --cov-config .coveragerc --cov=tosfs -l --tb=short --maxfail=1 tosfs/tests/test_fsspec_integration.py --ignore=tosfs/tests/test_stability.py
 
 .PHONY: test_stability
 test_stability:             ## Run stability tests.
diff --git a/tosfs/tests/test_fsspec_integration.py b/tosfs/tests/test_fsspec_integration.py
index 38433e8..d4ce00d 100644
--- a/tosfs/tests/test_fsspec_integration.py
+++ b/tosfs/tests/test_fsspec_integration.py
@@ -91,7 +91,7 @@ def test_customized_class(bucket, temporary_workspace):
         "class": "tosfs.tests.test_fsspec_integration.MyTosFileSystem"
     }
     fsspec.register_implementation(
-        "tos", "tosfs.tests.test_fsspec_integration.MyTosFileSystem"
+        "tos", "tosfs.tests.test_fsspec_integration.MyTosFileSystem", True
     )
 
     logger.error("----------------")