diff --git a/api/src/app/services/activity.service.ts b/api/src/app/services/activity.service.ts
index b1a8178..e4c546f 100644
--- a/api/src/app/services/activity.service.ts
+++ b/api/src/app/services/activity.service.ts
@@ -8,6 +8,10 @@ import type {
   Activity,
   ActivityFeedResponse,
   ActivityUser,
+  SuggestionActivity,
+  LikeActivity,
+  CommentActivity,
+  AchievementActivity,
 } from "@library/shared-types";
 import { ACHIEVEMENTS, ActivityType } from "@library/shared-types";
 import { prisma } from "../lib/prisma";
@@ -61,7 +65,7 @@ export class ActivityService {
     limit: number,
     offset: number,
     userId?: string
-  ) {
+  ): Promise<SuggestionActivity[]> {
     const where = userId
       ? { userId, user: { profilePublic: true, isBanned: false } }
       : { user: { profilePublic: true, isBanned: false } };
@@ -104,7 +108,7 @@ export class ActivityService {
     limit: number,
     offset: number,
     userId?: string
-  ) {
+  ): Promise<LikeActivity[]> {
     const where = userId
       ? { userId, user: { profilePublic: true, isBanned: false } }
       : { user: { profilePublic: true, isBanned: false } };
@@ -131,7 +135,7 @@ export class ActivityService {
 
     // For each like, fetch the entity title
     const likesWithTitles = await Promise.all(
-      likes.map(async (like) => {
+      likes.map(async (like): Promise<LikeActivity> => {
         const entityTitle = await this.getEntityTitle(
           like.entityType,
           like.entityId
@@ -158,7 +162,7 @@ export class ActivityService {
     limit: number,
     offset: number,
     userId?: string
-  ) {
+  ): Promise<CommentActivity[]> {
     const where = userId
       ? { userId, user: { profilePublic: true, isBanned: false } }
       : { user: { profilePublic: true, isBanned: false } };
@@ -246,7 +250,7 @@ export class ActivityService {
     limit: number,
     offset: number,
     userId?: string
-  ) {
+  ): Promise<AchievementActivity[]> {
     const where = userId
       ? {
           userId,