diff --git a/.changeset/fix-configurable-connection-props.md b/.changeset/fix-configurable-connection-props.md
new file mode 100644
index 00000000..476e326e
--- /dev/null
+++ b/.changeset/fix-configurable-connection-props.md
@@ -0,0 +1,7 @@
+---
+"partyserver": patch
+---
+
+Add `configurable: true` to `id`, `tags`, and `socket` property descriptors in `createLazyConnection` to fix Vite HMR compatibility
+
+When using PartyServer with Vite's Cloudflare Workers dev mode, HMR reloads recreate the module-scoped `WeakSet` used to track wrapped sockets, while the underlying WebSocket instances survive. This caused `Object.defineProperties` to throw `TypeError: Cannot redefine property` on properties that were missing the `configurable` flag.
diff --git a/packages/partyserver/CHANGELOG.md b/packages/partyserver/CHANGELOG.md
index 3a943d0c..67063c88 100644
--- a/packages/partyserver/CHANGELOG.md
+++ b/packages/partyserver/CHANGELOG.md
@@ -292,14 +292,12 @@
 ### Patch Changes
 
 - [`528adea`](https://github.com/threepointone/partyserver/commit/528adeaced6dce6e888d2f54cc75c3569bf2c277) Thanks [@threepointone](https://github.com/threepointone)! - some fixes and tweaks
-
   - getServerByName was throwing on all requests
   - `Env` is now an optional arg when defining `Server`
   - `y-partyserver/provider` can now take an optional `prefix` arg to use a custom url to connect
   - `routePartyKitRequest`/`getServerByName` now accepts `jurisdiction`
 
   bonus:
-
   - added a bunch of fixtures
   - added stubs for docs
 
diff --git a/packages/partyserver/src/connection.ts b/packages/partyserver/src/connection.ts
index f1e2217a..4d71fd86 100644
--- a/packages/partyserver/src/connection.ts
+++ b/packages/partyserver/src/connection.ts
@@ -132,17 +132,20 @@ export const createLazyConnection = (
 
   const connection = Object.defineProperties(ws, {
     id: {
+      configurable: true,
       get() {
         return attachments.get(ws).__pk.id;
       }
     },
     tags: {
+      configurable: true,
       get() {
         // Default to [] for connections accepted before tags were stored
         return attachments.get(ws).__pk.tags ?? [];
       }
     },
     socket: {
+      configurable: true,
       get() {
         return ws;
       }
diff --git a/packages/y-partyserver/CHANGELOG.md b/packages/y-partyserver/CHANGELOG.md
index ca1a6675..5cfe345a 100644
--- a/packages/y-partyserver/CHANGELOG.md
+++ b/packages/y-partyserver/CHANGELOG.md
@@ -25,7 +25,6 @@
 - [#341](https://github.com/cloudflare/partykit/pull/341) [`e7f4b51`](https://github.com/cloudflare/partykit/commit/e7f4b51198904273befb1d39478840c628f6e2b1) Thanks [@threepointone](https://github.com/threepointone)! - Fix Yjs hibernation support and awareness propagation
 
   **Server:**
-
   - Replace in-memory `WSSharedDoc.conns` Map with `connection.setState()` and `getConnections()` so connection tracking survives Durable Object hibernation
   - Move event handler registration from `WSSharedDoc` constructor into `onStart()` to use `getConnections()` for broadcasting
   - Disable awareness protocol's built-in `_checkInterval` in `WSSharedDoc` constructor to prevent timers from defeating hibernation
@@ -35,7 +34,6 @@
   - Widen `onLoad()` return type to `Promise<YDoc | void>` to allow seeding the document from a returned YDoc
 
   **Provider:**
-
   - Switch awareness event listener from `"update"` to `"change"` so clock-only heartbeat renewals do not produce network traffic (allows DO hibernation during idle sessions)
   - Disable awareness protocol's built-in `_checkInterval` on the client to stop 15-second clock renewals and 30-second peer timeout removal
   - Remove provider's own `_checkInterval` liveness timer (was coupled to the awareness heartbeat)
@@ -370,14 +368,12 @@
 ### Patch Changes
 
 - [`528adea`](https://github.com/threepointone/partyserver/commit/528adeaced6dce6e888d2f54cc75c3569bf2c277) Thanks [@threepointone](https://github.com/threepointone)! - some fixes and tweaks
-
   - getServerByName was throwing on all requests
   - `Env` is now an optional arg when defining `Server`
   - `y-partyserver/provider` can now take an optional `prefix` arg to use a custom url to connect
   - `routePartyKitRequest`/`getServerByName` now accepts `jurisdiction`
 
   bonus:
-
   - added a bunch of fixtures
   - added stubs for docs