diff --git a/reviewboard/admin/forms/diff_settings.py b/reviewboard/admin/forms/diff_settings.py
index 3e340bd6af08d051e3d65c366db321add8417e5c..bd2db03bf1e1d83dce40b2360df0651d4d1ac7c2 100644
--- a/reviewboard/admin/forms/diff_settings.py
+++ b/reviewboard/admin/forms/diff_settings.py
@@ -156,16 +156,14 @@ def load(self) -> None:
         """
         super().load()
 
-        siteconfig = self.siteconfig
-
         # Load the settings from the Trojan Code checker.
         #
         # In the future, we may want to expand this to dynamically support
         # any and all registered code safety checkers, but that will require
         # additional support in the checkers.
         code_safety_config = cast(
             Dict[str, Dict[str, Any]],
-            siteconfig.get('code_safety_checkers'))
+            self.get_key_value('code_safety_checkers'))
         trojan_source_config = code_safety_config.get(
             TrojanSourceCodeSafetyChecker.checker_id, {})
 
@@ -179,28 +177,26 @@ def load(self) -> None:
         # Load the "Show all whitespace for" setting.
         self.fields['include_space_patterns'].initial = ', '.join(
             cast(List[str],
-                 siteconfig.get('diffviewer_include_space_patterns')))
+                 self.get_key_value('diffviewer_include_space_patterns')))
 
     def save(self) -> None:
         """Save the form.
 
         This will write the new configuration to the database.
         """
-        siteconfig = self.siteconfig
-
         # Store the settings for the Trojan Code checker.
         code_safety_config = cast(
             Dict[str, Any],
-            siteconfig.get('code_safety_checkers'))
+            self.get_key_value('code_safety_checkers'))
         code_safety_config[TrojanSourceCodeSafetyChecker.checker_id] = {
             key: self.cleaned_data[f'trojan_source_{key}']
             for key in ('check_confusables',
                         'confusable_aliases_allowed')
         }
-        siteconfig.set('code_safety_checkers', code_safety_config)
+        self.set_key_value('code_safety_checkers', code_safety_config)
 
         # Save the "Show all whitespace for" setting.
-        siteconfig.set(
+        self.set_key_value(
             'diffviewer_include_space_patterns',
             re.split(r',\s*', self.cleaned_data['include_space_patterns']))