diff --git a/packages/database/prisma/migrations/20241219153556_comments_user/migration.sql b/packages/database/prisma/migrations/20241219153556_comments_user/migration.sql
new file mode 100644
index 000000000..838d63eb5
--- /dev/null
+++ b/packages/database/prisma/migrations/20241219153556_comments_user/migration.sql
@@ -0,0 +1,33 @@
+-- Create guest users for comments without user_id and link them
+DO $$
+DECLARE
+    comment_record RECORD;
+BEGIN
+    FOR comment_record IN 
+        SELECT id, author_name 
+        FROM comments 
+        WHERE user_id IS NULL
+    LOOP
+        WITH new_user AS (
+            INSERT INTO users (id, is_guest, created_at)
+            VALUES (
+                gen_random_uuid()::text,
+                TRUE,
+                NOW()
+            )
+            RETURNING id
+        )
+        UPDATE comments
+        SET user_id = (SELECT id FROM new_user)
+        WHERE id = comment_record.id;
+    END LOOP;
+END;
+$$; 
+-- DropForeignKey
+ALTER TABLE "comments" DROP CONSTRAINT "comments_user_id_fkey";
+
+-- AlterTable
+ALTER TABLE "comments" ALTER COLUMN "user_id" SET NOT NULL;
+
+-- AddForeignKey
+ALTER TABLE "comments" ADD CONSTRAINT "comments_user_id_fkey" FOREIGN KEY ("user_id") REFERENCES "users"("id") ON DELETE RESTRICT ON UPDATE CASCADE;
diff --git a/packages/database/prisma/schema.prisma b/packages/database/prisma/schema.prisma
index a283beb15..0cf5c8bad 100644
--- a/packages/database/prisma/schema.prisma
+++ b/packages/database/prisma/schema.prisma
@@ -243,12 +243,12 @@ model Comment {
   content    String
   pollId     String    @map("poll_id")
   authorName String    @map("author_name")
-  user       User?     @relation(fields: [userId], references: [id])
-  userId     String?   @map("user_id")
+  userId     String    @map("user_id")
   createdAt  DateTime  @default(now()) @map("created_at")
   updatedAt  DateTime? @updatedAt @map("updated_at")
 
   poll Poll @relation("PollToComments", fields: [pollId], references: [id], onDelete: Cascade)
+  user User @relation(fields: [userId], references: [id])
 
   @@index([pollId], type: Hash)
   @@map("comments")