diff --git a/src/storage/adapters/fileSystemStorage.ts b/src/storage/adapters/fileSystemStorage.ts
index fa0715df..5ec1d88e 100644
--- a/src/storage/adapters/fileSystemStorage.ts
+++ b/src/storage/adapters/fileSystemStorage.ts
@@ -2467,6 +2467,15 @@ export class FileSystemStorage extends BaseStorage {
             )
             this.flushWatcher?.close()
             this.flushWatcher = undefined
+            // The SAFETY sweep must go first. It is already armed at 30s, and
+            // startFlushRequestPolling() declines to arm over an existing
+            // interval — so leaving it would quietly leave this store answering
+            // flush requests on a 30s cadence instead of the 500ms one the door
+            // promises. A degrade nobody asked for is still a degrade.
+            if (this.flushWatcherInterval) {
+              clearInterval(this.flushWatcherInterval)
+              this.flushWatcherInterval = undefined
+            }
             this.startFlushRequestPolling(sweep)
           })
           if (typeof watcher.unref === 'function') watcher.unref()