diff --git a/assets/oh-my-opencode.schema.json b/assets/oh-my-opencode.schema.json
index f63a98e24..cfe085234 100644
--- a/assets/oh-my-opencode.schema.json
+++ b/assets/oh-my-opencode.schema.json
@@ -5744,6 +5744,10 @@
           "type": "number",
           "minimum": 10000
         },
+        "taskCleanupDelayMs": {
+          "type": "number",
+          "minimum": 60000
+        },
         "syncPollTimeoutMs": {
           "type": "number",
           "minimum": 60000
diff --git a/src/config/schema/background-task.ts b/src/config/schema/background-task.ts
index 4b62612fa..415ef274b 100644
--- a/src/config/schema/background-task.ts
+++ b/src/config/schema/background-task.ts
@@ -19,6 +19,8 @@ export const BackgroundTaskConfigSchema = z.object({
   taskTtlMs: z.number().min(300000).optional(),
   /** Timeout for tasks whose session has completely disappeared from the status registry (default: 60000 = 1 minute, minimum: 10000 = 10 seconds). When a session is gone (likely crashed), this shorter timeout is used instead of the normal stale timeout. */
   sessionGoneTimeoutMs: z.number().min(10000).optional(),
+  /** Delay before removing completed/cancelled/errored tasks from memory in milliseconds (default: 600000 = 10 minutes, minimum: 60000 = 1 minute). */
+  taskCleanupDelayMs: z.number().min(60000).optional(),
   syncPollTimeoutMs: z.number().min(60000).optional(),
   /** Maximum tool calls per subagent task before circuit breaker triggers (default: 200, minimum: 10). Prevents runaway loops from burning unlimited tokens. */
   maxToolCalls: z.number().int().min(10).optional(),
diff --git a/src/features/background-agent/manager.ts b/src/features/background-agent/manager.ts
index 3485461ca..bdedc17cc 100644
--- a/src/features/background-agent/manager.ts
+++ b/src/features/background-agent/manager.ts
@@ -2157,7 +2157,7 @@ The task was re-queued on a fallback model after a retryable failure.
         SessionCategoryRegistry.remove(task.sessionId)
       }
       log("[background-agent] Removed completed task from memory:", taskId)
-    }, TASK_CLEANUP_DELAY_MS)
+    }, this.config?.taskCleanupDelayMs ?? TASK_CLEANUP_DELAY_MS)
 
     this.completionTimers.set(taskId, timer)
   }