diff --git a/webapp/packages/core-localization/src/LocalizationService.ts b/webapp/packages/core-localization/src/LocalizationService.ts
index 4fe038cb59..9641210e5f 100644
--- a/webapp/packages/core-localization/src/LocalizationService.ts
+++ b/webapp/packages/core-localization/src/LocalizationService.ts
@@ -43,7 +43,7 @@ export class LocalizationService extends Bootstrap {
   }
 
   get defaultLanguage(): string {
-    if (this.pluginSettings.getValue('defaultLanguage')) {
+    if (this.pluginSettings.isValueDefault('defaultLanguage')) {
       return this.deprecatedPluginSettings.getValue('defaultLanguage');
     }
 
diff --git a/webapp/packages/core-theming/src/ThemeSettingsService.test.ts b/webapp/packages/core-theming/src/ThemeSettingsService.test.ts
index 3cc90236f4..459a85403f 100644
--- a/webapp/packages/core-theming/src/ThemeSettingsService.test.ts
+++ b/webapp/packages/core-theming/src/ThemeSettingsService.test.ts
@@ -35,7 +35,7 @@ const equalConfigA = {
   'core.user': {
     defaultTheme: testValueA,
   } as IThemeSettings,
-  plugin: {
+  core: {
     theming: {
       defaultTheme: testValueA,
     } as IThemeSettings,
@@ -46,7 +46,7 @@ const equalConfigB = {
   'core.user': {
     defaultTheme: testValueB,
   } as IThemeSettings,
-  plugin: {
+  core: {
     theming: {
       defaultTheme: testValueB,
     } as IThemeSettings,
diff --git a/webapp/packages/core-theming/src/ThemeSettingsService.ts b/webapp/packages/core-theming/src/ThemeSettingsService.ts
index 451dc4887e..aaa3502808 100644
--- a/webapp/packages/core-theming/src/ThemeSettingsService.ts
+++ b/webapp/packages/core-theming/src/ThemeSettingsService.ts
@@ -26,7 +26,7 @@ export class ThemeSettingsService {
   readonly deprecatedSettings: PluginSettings<IThemeSettings>;
 
   constructor(private readonly pluginManagerService: PluginManagerService) {
-    this.settings = this.pluginManagerService.getPluginSettings('theming', defaultThemeSettings);
+    this.settings = this.pluginManagerService.getCoreSettings('theming', defaultThemeSettings);
     this.deprecatedSettings = this.pluginManagerService.getCoreSettings('user', defaultThemeSettings);
   }
 }