diff --git a/src/services/group-sync.ts b/src/services/group-sync.ts
index 834434d..1165b4f 100644
--- a/src/services/group-sync.ts
+++ b/src/services/group-sync.ts
@@ -3,7 +3,7 @@ import { db } from '../db';
 const env = process.env;
 
 // In-memory cache for active groups
-const activeGroupsCache = new Map<string, string>(); // groupId -> groupName
+// const activeGroupsCache = new Map<string, string>(); // groupId -> groupName
 
 /**
  * Represents a group from the Evolution API response
@@ -36,6 +36,9 @@ export class GroupSyncService {
 	// Static property for DB instance injection (defaults to global db)
 	static dbInstance: Database = db;
 
+	// In-memory cache for active groups (made public for tests)
+	public static readonly activeGroupsCache = new Map<string, string>(); // groupId -> groupName
+
 	/**
 	 * Gets the sync interval duration in milliseconds.
 	 * 
@@ -199,11 +202,11 @@ export class GroupSyncService {
 
 	private static cacheActiveGroups(): void {
 		const groups = this.dbInstance.prepare('SELECT id, name FROM groups WHERE active = TRUE').all();
-		activeGroupsCache.clear();
+		this.activeGroupsCache.clear();
 		for (const group of groups) {
-			activeGroupsCache.set(group.id, group.name);
+			this.activeGroupsCache.set(group.id, group.name);
 		}
-		console.log(`Cached ${activeGroupsCache.size} active groups`);
+		console.log(`Cached ${this.activeGroupsCache.size} active groups`);
 	}
 
 	private static getActiveGroupsCount(): number {
@@ -330,6 +333,6 @@ export class GroupSyncService {
 	 * @returns True if the group is active, false otherwise.
 	 */
 	static isGroupActive(groupId: string): boolean {
-		return activeGroupsCache.has(groupId);
+		return this.activeGroupsCache.has(groupId);
 	}
 }
diff --git a/tests/unit/services/group-sync.test.ts b/tests/unit/services/group-sync.test.ts
index 3701a1e..44ee12c 100644
--- a/tests/unit/services/group-sync.test.ts
+++ b/tests/unit/services/group-sync.test.ts
@@ -149,7 +149,7 @@ describe('GroupSyncService', () => {
   describe('isGroupActive', () => {
     beforeEach(() => {
       // Clear cache and add test groups
-      GroupSyncService['activeGroupsCache'].clear();
+      GroupSyncService.activeGroupsCache.clear();
       db.exec('DELETE FROM groups');
       db.exec("INSERT INTO groups (id, name, active) VALUES ('active-group', 'Active Group', 1)");
       db.exec("INSERT INTO groups (id, name, active) VALUES ('inactive-group', 'Inactive Group', 0)");