diff --git a/src/db/repositories/drizzle/initiative.ts b/src/db/repositories/drizzle/initiative.ts
index 244482d..464043c 100644
--- a/src/db/repositories/drizzle/initiative.ts
+++ b/src/db/repositories/drizzle/initiative.ts
@@ -7,7 +7,7 @@
 import { eq } from 'drizzle-orm';
 import { nanoid } from 'nanoid';
 import type { DrizzleDatabase } from '../../index.js';
-import { initiatives, type Initiative } from '../../schema.js';
+import { agents, initiatives, type Initiative } from '../../schema.js';
 import type {
   InitiativeRepository,
   CreateInitiativeData,
@@ -74,6 +74,10 @@ export class DrizzleInitiativeRepository implements InitiativeRepository {
   }
 
   async delete(id: string): Promise<void> {
+    // Detach agents before deleting — agents.initiative_id FK may lack ON DELETE SET NULL
+    // in databases that haven't applied migration 0025 yet.
+    await this.db.update(agents).set({ initiativeId: null }).where(eq(agents.initiativeId, id));
+
     const [deleted] = await this.db.delete(initiatives).where(eq(initiatives.id, id)).returning();
 
     if (!deleted) {