diff --git a/backend/app/api/agent.py b/backend/app/api/agent.py
index 1c4ed53c..88921a01 100644
--- a/backend/app/api/agent.py
+++ b/backend/app/api/agent.py
@@ -17,6 +17,7 @@ from app.api import tasks as tasks_api
 from app.api.deps import ActorContext, get_board_or_404, get_task_or_404
 from app.core.agent_auth import AgentAuthContext, get_agent_auth_context
 from app.core.config import settings
+from app.core.time import utcnow
 from app.db.pagination import paginate
 from app.db.session import get_session
 from app.integrations.openclaw_gateway import GatewayConfig as GatewayClientConfig
@@ -572,6 +573,12 @@ async def update_agent_soul(
             status_code=status.HTTP_422_UNPROCESSABLE_ENTITY,
             detail="content is required",
         )
+
+    # Persist the SOUL in the DB so future reprovision/update doesn't overwrite it.
+    target.soul_template = content
+    target.updated_at = utcnow()
+    session.add(target)
+    await session.commit()
     try:
         await openclaw_call(
             "agents.files.set",
diff --git a/templates/HEARTBEAT_LEAD.md b/templates/HEARTBEAT_LEAD.md
index bb9da903..95f56d8b 100644
--- a/templates/HEARTBEAT_LEAD.md
+++ b/templates/HEARTBEAT_LEAD.md
@@ -321,6 +321,7 @@ Tools:
 - Update an agent's SOUL.md (lead-only):
   PUT $BASE_URL/api/v1/agent/boards/$BOARD_ID/agents/<AGENT_ID>/soul
   Body: {"content":"<new SOUL.md>","source_url":"<optional>","reason":"<optional>"}
+  Notes: this persists as the agent's `soul_template` so future reprovision won't overwrite it.
 
 ## Memory Maintenance (every 2-3 days)
 Lightweight consolidation (modeled on human "sleep consolidation"):