diff --git a/tests/conftest.py b/tests/conftest.py
index 58cf85d8..214f5203 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -1,5 +1,4 @@
 import os
-import pkgutil
 import sys
 
 import pytest
@@ -96,37 +95,6 @@ def leak_detector():
     assert leaks == []
 
 
-@pytest.fixture(params=(True, False))
-def limit_loader(request, monkeypatch):
-    """Patch pkgutil.get_loader to give loader without get_filename or archive.
-
-    This provides for tests where a system has custom loaders, e.g. Google App
-    Engine's HardenedModulesHook, which have neither the `get_filename` method
-    nor the `archive` attribute.
-
-    This fixture will run the testcase twice, once with and once without the
-    limitation/mock.
-    """
-    if not request.param:
-        return
-
-    class LimitedLoader:
-        def __init__(self, loader):
-            self.loader = loader
-
-        def __getattr__(self, name):
-            if name in {"archive", "get_filename"}:
-                raise AttributeError(f"Mocking a loader which does not have {name!r}.")
-            return getattr(self.loader, name)
-
-    old_get_loader = pkgutil.get_loader
-
-    def get_loader(*args, **kwargs):
-        return LimitedLoader(old_get_loader(*args, **kwargs))
-
-    monkeypatch.setattr(pkgutil, "get_loader", get_loader)
-
-
 @pytest.fixture
 def modules_tmp_path(tmp_path, monkeypatch):
     """A temporary directory added to sys.path."""
diff --git a/tests/test_instance_config.py b/tests/test_instance_config.py
index 1918bd99..835a8784 100644
--- a/tests/test_instance_config.py
+++ b/tests/test_instance_config.py
@@ -63,7 +63,7 @@ def test_uninstalled_namespace_paths(tmp_path, monkeypatch, purge_module):
 
 
 def test_installed_module_paths(
-    modules_tmp_path, modules_tmp_path_prefix, purge_module, site_packages, limit_loader
+    modules_tmp_path, modules_tmp_path_prefix, purge_module, site_packages
 ):
     (site_packages / "site_app.py").write_text(
         "import flask\napp = flask.Flask(__name__)\n"
@@ -78,7 +78,7 @@ def test_installed_module_paths(
 
 
 def test_installed_package_paths(
-    limit_loader, modules_tmp_path, modules_tmp_path_prefix, purge_module, monkeypatch
+    modules_tmp_path, modules_tmp_path_prefix, purge_module, monkeypatch
 ):
     installed_path = modules_tmp_path / "path"
     installed_path.mkdir()
@@ -97,7 +97,7 @@ def test_installed_package_paths(
 
 
 def test_prefix_package_paths(
-    limit_loader, modules_tmp_path, modules_tmp_path_prefix, purge_module, site_packages
+    modules_tmp_path, modules_tmp_path_prefix, purge_module, site_packages
 ):
     app = site_packages / "site_package"
     app.mkdir()