diff --git a/packages/backend/src/server/api/SigninService.ts b/packages/backend/src/server/api/SigninService.ts
index 96a89956f..671278a18 100644
--- a/packages/backend/src/server/api/SigninService.ts
+++ b/packages/backend/src/server/api/SigninService.ts
@@ -43,7 +43,7 @@ export class SigninService {
 
 		if (redirect) {
 			//#region Cookie
-			reply.cookies.set('igi', user.token!, {
+			reply.setCookie('igi', user.token!, {
 				path: '/',
 				// SEE: https://github.com/koajs/koa/issues/974
 				// When using a SSL proxy it should be configured to add the "X-Forwarded-Proto: https" header
diff --git a/packages/backend/src/server/api/integration/DiscordServerService.ts b/packages/backend/src/server/api/integration/DiscordServerService.ts
index a7f39a78d..e6e79f3d3 100644
--- a/packages/backend/src/server/api/integration/DiscordServerService.ts
+++ b/packages/backend/src/server/api/integration/DiscordServerService.ts
@@ -122,7 +122,7 @@ export class DiscordServerService {
 				response_type: 'code',
 			};
 
-			reply.cookies.set('signin_with_discord_sid', sessid, {
+			reply.setCookie('signin_with_discord_sid', sessid, {
 				path: '/',
 				secure: this.config.url.startsWith('https'),
 				httpOnly: true,
diff --git a/packages/backend/src/server/api/integration/GithubServerService.ts b/packages/backend/src/server/api/integration/GithubServerService.ts
index 186748dab..e6c42e1ee 100644
--- a/packages/backend/src/server/api/integration/GithubServerService.ts
+++ b/packages/backend/src/server/api/integration/GithubServerService.ts
@@ -120,7 +120,7 @@ export class GithubServerService {
 				state: uuid(),
 			};
 
-			reply.cookies.set('signin_with_github_sid', sessid, {
+			reply.setCookie('signin_with_github_sid', sessid, {
 				path: '/',
 				secure: this.config.url.startsWith('https'),
 				httpOnly: true,
diff --git a/packages/backend/src/server/api/integration/TwitterServerService.ts b/packages/backend/src/server/api/integration/TwitterServerService.ts
index 7a127fa29..747f59c7a 100644
--- a/packages/backend/src/server/api/integration/TwitterServerService.ts
+++ b/packages/backend/src/server/api/integration/TwitterServerService.ts
@@ -112,7 +112,7 @@ export class TwitterServerService {
 
 			this.redisClient.set(sessid, JSON.stringify(twCtx));
 
-			reply.cookies.set('signin_with_twitter_sid', sessid, {
+			reply.setCookie('signin_with_twitter_sid', sessid, {
 				path: '/',
 				secure: this.config.url.startsWith('https'),
 				httpOnly: true,