diff --git a/server/seed.ts b/server/seed.ts
index aa8033a..aa004ca 100644
--- a/server/seed.ts
+++ b/server/seed.ts
@@ -193,9 +193,18 @@ const seedArticles = [
 ];
 
 export async function seedDatabase() {
+  const validSlugs = new Set(seedArticles.map((a) => a.slug));
   const existing = await storage.getArticles();
   const existingSlugs = new Set(existing.map((a) => a.slug));
 
+  const toDelete = existing.filter((a) => !validSlugs.has(a.slug));
+  if (toDelete.length > 0) {
+    for (const article of toDelete) {
+      await db.execute(sql`DELETE FROM articles WHERE id = ${article.id}`);
+    }
+    console.log("Cleanup: removed " + toDelete.length + " articles not in seed list.");
+  }
+
   let added = 0;
   for (const article of seedArticles) {
     if (existingSlugs.has(article.slug)) continue;