diff --git a/djblets/testing/testcases.py b/djblets/testing/testcases.py
index ad9853965320e9a21cbe0a928910eedf5aace7ce..b090fdd62967a1911b417aa88816f0a6158bc292 100644
--- a/djblets/testing/testcases.py
+++ b/djblets/testing/testcases.py
@@ -698,18 +698,19 @@
             for db in databases:
                 cls.load_fixtures(fixtures, db=db)
 
-    def _fixture_setup(self) -> None:
+    @classmethod
+    def _fixture_setup(cls) -> None:
         """Set up fixtures for unit tests."""
         # TestCase._fixture_setup shouldn't actually load fixtures on any
         # database other than the dummy backend (confusingly enough), but
         # it does call _enter_atomics(), which sets up necessary state.
-        fixtures = self.fixtures
-        self.fixtures = None
+        fixtures = cls.fixtures
+        cls.fixtures = None
 
         try:
             super()._fixture_setup()
         finally:
-            self.fixtures = fixtures
+            cls.fixtures = fixtures
 
     @classmethod
     def load_fixtures(