diff --git a/main.js b/main.js
index ec853ec1..f1ee5a38 100644
--- a/main.js
+++ b/main.js
@@ -2244,6 +2244,13 @@ function firstPartyAddonIds() {
       } catch {}
     }
   } catch {}
+  // Ids that have ever shipped inside Theseus stay reserved even after they
+  // leave the bundle: their extensions-data/<id>.json and vault.derive
+  // namespace (e.g. pithos/sia-recovery/v1) outlive them, and a community
+  // add-on installed under a dropped id would inherit both.
+  for (const id of ["bchwallet", "siawallet", "aegis", "blocker", "consent", "docx-editor", "notepad", "pdf-editor", "pithos", "screenshot", "translate", "vpn"]) {
+    if (!bundled.has(id)) absorbed.add(id);
+  }
   firstPartyIdsCache = { bundled, absorbed };
   return firstPartyIdsCache;
 }