diff --git a/src/addons/privatefiles/services/privatefiles.ts b/src/addons/privatefiles/services/privatefiles.ts
index e816bbd09..6f681d7eb 100644
--- a/src/addons/privatefiles/services/privatefiles.ts
+++ b/src/addons/privatefiles/services/privatefiles.ts
@@ -20,6 +20,8 @@ import { CoreWSExternalWarning } from '@services/ws';
 import { CoreSite } from '@classes/site';
 import { makeSingleton } from '@singletons/core.singletons';
 
+const ROOT_CACHE_KEY = 'mmaFiles:';
+
 /**
  * Service to handle my files and site files.
  */
@@ -32,8 +34,6 @@ export class AddonPrivateFilesProvider {
     static readonly PRIVATE_FILES_COMPONENT = 'mmaFilesMy';
     static readonly SITE_FILES_COMPONENT = 'mmaFilesSite';
 
-    protected readonly ROOT_CACHE_KEY = 'mmaFiles:';
-
     /**
      * Check if core_user_get_private_files_info WS call is available.
      *
@@ -125,7 +125,7 @@ export class AddonPrivateFilesProvider {
     protected getFilesListCacheKey(params: AddonPrivateFilesGetFilesWSParams): string {
         const root = !params.component ? 'site' : 'my';
 
-        return this.ROOT_CACHE_KEY + 'list:' + root + ':' + params.contextid + ':' + params.filepath;
+        return ROOT_CACHE_KEY + 'list:' + root + ':' + params.contextid + ':' + params.filepath;
     }
 
     /**
@@ -194,7 +194,7 @@ export class AddonPrivateFilesProvider {
      * @return Cache key.
      */
     protected getPrivateFilesInfoCommonCacheKey(): string {
-        return this.ROOT_CACHE_KEY + 'privateInfo';
+        return ROOT_CACHE_KEY + 'privateInfo';
     }
 
     /**
diff --git a/src/core/services/groups.ts b/src/core/services/groups.ts
index b82596a84..e4bc4f0e0 100644
--- a/src/core/services/groups.ts
+++ b/src/core/services/groups.ts
@@ -21,6 +21,8 @@ import { makeSingleton, Translate } from '@singletons/core.singletons';
 import { CoreWSExternalWarning } from '@services/ws';
 import { CoreCourseBase } from '@/types/global';
 
+const ROOT_CACHE_KEY = 'mmGroups:';
+
 /*
  * Service to handle groups.
 */
@@ -31,7 +33,6 @@ export class CoreGroupsProvider {
     static readonly NOGROUPS = 0;
     static readonly SEPARATEGROUPS = 1;
     static readonly VISIBLEGROUPS = 2;
-    protected readonly ROOT_CACHE_KEY = 'mmGroups:';
 
     /**
      * Check if group mode of an activity is enabled.
@@ -102,7 +103,7 @@ export class CoreGroupsProvider {
      * @return Cache key.
      */
     protected getActivityAllowedGroupsCacheKey(cmId: number, userId: number): string {
-        return this.ROOT_CACHE_KEY + 'allowedgroups:' + cmId + ':' + userId;
+        return ROOT_CACHE_KEY + 'allowedgroups:' + cmId + ':' + userId;
     }
 
     /**
@@ -225,7 +226,7 @@ export class CoreGroupsProvider {
      * @return Cache key.
      */
     protected getActivityGroupModeCacheKey(cmId: number): string {
-        return this.ROOT_CACHE_KEY + 'groupmode:' + cmId;
+        return ROOT_CACHE_KEY + 'groupmode:' + cmId;
     }
 
     /**
@@ -299,7 +300,7 @@ export class CoreGroupsProvider {
      * @return Prefix Cache key.
      */
     protected getUserGroupsInCoursePrefixCacheKey(): string {
-        return this.ROOT_CACHE_KEY + 'courseGroups:';
+        return ROOT_CACHE_KEY + 'courseGroups:';
     }
 
     /**