diff --git a/tests/base.py b/tests/base.py
index 480db83..f6982f5 100755
--- a/tests/base.py
+++ b/tests/base.py
@@ -2791,6 +2791,41 @@
             files)
         return before
 
+    def newTenantConfig(self, source_name):
+        """ Use this to update the tenant config file in tests
+
+        This will update self.tenant_config_file to point to a temporary file
+        for the duration of this particular test. The content of that file will
+        be taken from FIXTURE_DIR/source_name
+
+        After the test the original value of self.tenant_config_file will be
+        restored.
+
+        :arg str source_name: The path of the file under
+            FIXTURE_DIR that will be used to populate the new tenant
+            config file.
+        """
+        source_path = os.path.join(FIXTURE_DIR, source_name)
+        orig_tenant_config_file = self.tenant_config_file
+        with tempfile.NamedTemporaryFile(
+            delete=False, mode='wb') as new_tenant_config:
+            self.tenant_config_file = new_tenant_config.name
+            with open(source_path, mode='rb') as source_tenant_config:
+                new_tenant_config.write(source_tenant_config.read())
+        self.config['scheduler']['tenant_config'] = self.tenant_config_file
+        self.setupAllProjectKeys()
+        self.log.debug(
+            'tenant_config_file = {}'.format(self.tenant_config_file))
+
+        def _restoreTenantConfig():
+            self.log.debug(
+                'restoring tenant_config_file = {}'.format(
+                    orig_tenant_config_file))
+            os.unlink(self.tenant_config_file)
+            self.tenant_config_file = orig_tenant_config_file
+            self.config['scheduler']['tenant_config'] = orig_tenant_config_file
+        self.addCleanup(_restoreTenantConfig)
+
     def addEvent(self, connection, event):
 
         """Inject a Fake (Gerrit) event.