diff --git a/server/entity/UserPushSubscription.ts b/server/entity/UserPushSubscription.ts
index b3c4d5d2b..e35a01548 100644
--- a/server/entity/UserPushSubscription.ts
+++ b/server/entity/UserPushSubscription.ts
@@ -1,8 +1,15 @@
 import { DbAwareColumn } from '@server/utils/DbColumnHelper';
-import { Column, Entity, ManyToOne, PrimaryGeneratedColumn } from 'typeorm';
+import {
+  Column,
+  Entity,
+  ManyToOne,
+  PrimaryGeneratedColumn,
+  Unique,
+} from 'typeorm';
 import { User } from './User';
 
 @Entity()
+@Unique(['endpoint', 'user'])
 export class UserPushSubscription {
   @PrimaryGeneratedColumn()
   public id: number;
diff --git a/server/migration/postgres/1765233385034-AddUniqueConstraintToPushSubscription.ts b/server/migration/postgres/1765233385034-AddUniqueConstraintToPushSubscription.ts
new file mode 100644
index 000000000..af245cfd6
--- /dev/null
+++ b/server/migration/postgres/1765233385034-AddUniqueConstraintToPushSubscription.ts
@@ -0,0 +1,19 @@
+import type { MigrationInterface, QueryRunner } from 'typeorm';
+
+export class AddUniqueConstraintToPushSubscription1765233385034
+  implements MigrationInterface
+{
+  name = 'AddUniqueConstraintToPushSubscription1765233385034';
+
+  public async up(queryRunner: QueryRunner): Promise<void> {
+    await queryRunner.query(
+      `ALTER TABLE "user_push_subscription" ADD CONSTRAINT "UQ_6427d07d9a171a3a1ab87480005" UNIQUE ("endpoint", "userId")`
+    );
+  }
+
+  public async down(queryRunner: QueryRunner): Promise<void> {
+    await queryRunner.query(
+      `ALTER TABLE "user_push_subscription" DROP CONSTRAINT "UQ_6427d07d9a171a3a1ab87480005"`
+    );
+  }
+}
diff --git a/server/migration/sqlite/1765233385034-AddUniqueConstraintToPushSubscription.ts b/server/migration/sqlite/1765233385034-AddUniqueConstraintToPushSubscription.ts
new file mode 100755
index 000000000..48a8c6d65
--- /dev/null
+++ b/server/migration/sqlite/1765233385034-AddUniqueConstraintToPushSubscription.ts
@@ -0,0 +1,17 @@
+import type { MigrationInterface, QueryRunner } from 'typeorm';
+
+export class AddUniqueConstraintToPushSubscription1765233385034
+  implements MigrationInterface
+{
+  name = 'AddUniqueConstraintToPushSubscription1765233385034';
+
+  public async up(queryRunner: QueryRunner): Promise<void> {
+    await queryRunner.query(
+      `CREATE UNIQUE INDEX "UQ_6427d07d9a171a3a1ab87480005" ON "user_push_subscription" ("endpoint", "userId")`
+    );
+  }
+
+  public async down(queryRunner: QueryRunner): Promise<void> {
+    await queryRunner.query(`DROP INDEX "UQ_6427d07d9a171a3a1ab87480005"`);
+  }
+}