diff --git a/modules/BlueskyNSE/NotificationService.swift b/modules/BlueskyNSE/NotificationService.swift
index d81b83a6bb..449fea8492 100644
--- a/modules/BlueskyNSE/NotificationService.swift
+++ b/modules/BlueskyNSE/NotificationService.swift
@@ -250,9 +250,48 @@ class NotificationService: UNNotificationServiceExtension {
       return nil
     }
 
+    pruneOldAvatars(in: avatarsDir)
+
     return fileURL
   }
 
+  // Best-effort, age-based cleanup of the avatar cache. We never delete files
+  // right after delivering a notification because the system reads them
+  // lazily (the Apple Watch may fetch the avatar seconds later), and the NSE
+  // gets no "notification dismissed" callback. Instead we drop files old
+  // enough that any device that needed them is long done. Notifications are
+  // ephemeral, so a one-day window is comfortably safe.
+  //
+  // This runs inside the time-limited extension, but the directory holds only
+  // a handful of small files. Every step is best-effort: multiple NSE
+  // instances may run this concurrently, so a file another instance just
+  // removed is expected and harmless (`try?`).
+  func pruneOldAvatars(
+    in directory: URL,
+    olderThan maxAge: TimeInterval = 24 * 60 * 60
+  ) {
+    let fileManager = FileManager.default
+    guard
+      let entries = try? fileManager.contentsOfDirectory(
+        at: directory,
+        includingPropertiesForKeys: [.contentModificationDateKey],
+        options: .skipsHiddenFiles
+      )
+    else {
+      return
+    }
+
+    let cutoff = Date().addingTimeInterval(-maxAge)
+    for fileURL in entries {
+      let modified = (try? fileURL.resourceValues(
+        forKeys: [.contentModificationDateKey]
+      ))?.contentModificationDate
+      if let modified, modified < cutoff {
+        try? fileManager.removeItem(at: fileURL)
+      }
+    }
+  }
+
   // MARK: Mutations
 
   func mutateWithBadge(_ content: UNMutableNotificationContent) {
diff --git a/modules/BlueskyNSE/README.md b/modules/BlueskyNSE/README.md
index 51ed9dea55..021530088b 100644
--- a/modules/BlueskyNSE/README.md
+++ b/modules/BlueskyNSE/README.md
@@ -55,6 +55,8 @@ The avatar is downloaded from `senderAvatarUrl` (rewritten to the `avatar_thumbn
 
 This distinction matters for paired devices: an `INImage` backed by in-memory data renders on the iPhone but is not relayed to the Apple Watch, which then falls back to drawing a monogram from the sender's initials. Backing the image with a file URL the system can resolve lazily lets the Watch render the real avatar. Avatar files are written under `notification-avatars/` in the container and named by a stable hash of the (content-addressed) source URL, so notifications from the same sender reuse one file.
 
+Because the system reads these files lazily, they cannot be deleted as soon as the handler returns, and the extension gets no "notification dismissed" callback. Instead `pruneOldAvatars` performs best-effort, age-based cleanup (files older than 24 hours) each time a new avatar is written. Notifications are ephemeral, so by then any device that needed the file is done. The cleanup tolerates concurrent NSE instances removing the same file.
+
 ## Key Files
 
 | File | Purpose |