diff --git a/packages/backend/src/core/CacheService.ts b/packages/backend/src/core/CacheService.ts
index 4afcef02be..6725ebe75b 100644
--- a/packages/backend/src/core/CacheService.ts
+++ b/packages/backend/src/core/CacheService.ts
@@ -56,10 +56,10 @@ export class CacheService implements OnApplicationShutdown {
 	) {
 		//this.onMessage = this.onMessage.bind(this);
 
-		this.userByIdCache = new MemoryKVCache<MiUser>(Infinity);
-		this.localUserByNativeTokenCache = new MemoryKVCache<MiLocalUser | null>(Infinity);
-		this.localUserByIdCache = new MemoryKVCache<MiLocalUser>(Infinity);
-		this.uriPersonCache = new MemoryKVCache<MiUser | null>(Infinity);
+		this.userByIdCache = new MemoryKVCache<MiUser>(1000 * 60 * 5); // 5m
+		this.localUserByNativeTokenCache = new MemoryKVCache<MiLocalUser | null>(1000 * 60 * 5); // 5m
+		this.localUserByIdCache = new MemoryKVCache<MiLocalUser>(1000 * 60 * 5); // 5m
+		this.uriPersonCache = new MemoryKVCache<MiUser | null>(1000 * 60 * 5); // 5m
 
 		this.userProfileCache = new RedisKVCache<MiUserProfile>(this.redisClient, 'userProfile', {
 			lifetime: 1000 * 60 * 30, // 30m
diff --git a/packages/backend/src/core/UserKeypairService.ts b/packages/backend/src/core/UserKeypairService.ts
index 51ac99179a..eb7a95da3e 100644
--- a/packages/backend/src/core/UserKeypairService.ts
+++ b/packages/backend/src/core/UserKeypairService.ts
@@ -25,7 +25,7 @@ export class UserKeypairService implements OnApplicationShutdown {
 	) {
 		this.cache = new RedisKVCache<MiUserKeypair>(this.redisClient, 'userKeypair', {
 			lifetime: 1000 * 60 * 60 * 24, // 24h
-			memoryCacheLifetime: Infinity,
+			memoryCacheLifetime: 1000 * 60 * 60 * 12, // 12h
 			fetcher: (key) => this.userKeypairsRepository.findOneByOrFail({ userId: key }),
 			toRedisConverter: (value) => JSON.stringify(value),
 			fromRedisConverter: (value) => JSON.parse(value),
diff --git a/packages/backend/src/core/activitypub/ApDbResolverService.ts b/packages/backend/src/core/activitypub/ApDbResolverService.ts
index 44680a2ed5..062af39732 100644
--- a/packages/backend/src/core/activitypub/ApDbResolverService.ts
+++ b/packages/backend/src/core/activitypub/ApDbResolverService.ts
@@ -54,8 +54,8 @@ export class ApDbResolverService implements OnApplicationShutdown {
 		private cacheService: CacheService,
 		private apPersonService: ApPersonService,
 	) {
-		this.publicKeyCache = new MemoryKVCache<MiUserPublickey | null>(Infinity);
-		this.publicKeyByUserIdCache = new MemoryKVCache<MiUserPublickey | null>(Infinity);
+		this.publicKeyCache = new MemoryKVCache<MiUserPublickey | null>(1000 * 60 * 60 * 12); // 12h
+		this.publicKeyByUserIdCache = new MemoryKVCache<MiUserPublickey | null>(1000 * 60 * 60 * 12); // 12h
 	}
 
 	@bindThis
diff --git a/packages/backend/src/server/api/AuthenticateService.ts b/packages/backend/src/server/api/AuthenticateService.ts
index ddef8db987..690ff2e022 100644
--- a/packages/backend/src/server/api/AuthenticateService.ts
+++ b/packages/backend/src/server/api/AuthenticateService.ts
@@ -37,7 +37,7 @@ export class AuthenticateService implements OnApplicationShutdown {
 
 		private cacheService: CacheService,
 	) {
-		this.appCache = new MemoryKVCache<MiApp>(Infinity);
+		this.appCache = new MemoryKVCache<MiApp>(1000 * 60 * 60 * 24 * 7); // 1w
 	}
 
 	@bindThis