diff --git a/src/platform/web/sync/SyncProxy.ts b/src/platform/web/sync/SyncProxy.ts
index 8d96ce5d4e..bd5d422983 100644
--- a/src/platform/web/sync/SyncProxy.ts
+++ b/src/platform/web/sync/SyncProxy.ts
@@ -27,7 +27,9 @@ export class SyncProxy implements ISync {
     }
 
     async start(): Promise<void> {
-        this._worker = new SharedWorker(new URL("./sync-worker", import.meta.url));
+        this._worker = new SharedWorker(new URL("./sync-worker", import.meta.url), {
+            type: "module",
+        });
         this._worker.port.onmessage = (event: MessageEvent) => {
             // TODO
             console.log(event);
diff --git a/src/platform/web/sync/sync-worker.js b/src/platform/web/sync/sync-worker.js
deleted file mode 100644
index c70e4e233b..0000000000
--- a/src/platform/web/sync/sync-worker.js
+++ /dev/null
@@ -1,7 +0,0 @@
-// TODO
-
-self.onconnect = (event) => {
-    const port = event.ports[0];
-    port.postMessage("hello from sync worker");
-    console.log("hello from sync worker");
-}
diff --git a/src/platform/web/sync/sync-worker.ts b/src/platform/web/sync/sync-worker.ts
new file mode 100644
index 0000000000..be7a1f6751
--- /dev/null
+++ b/src/platform/web/sync/sync-worker.ts
@@ -0,0 +1,12 @@
+/// <reference lib="webworker" />
+
+// The empty export makes this a module. It can be removed once there's at least one import.
+export {}
+
+declare let self: SharedWorkerGlobalScope;
+
+self.onconnect = (event: MessageEvent) => {
+    const port = event.ports[0];
+    port.postMessage("hello from sync worker");
+    console.log("hello from sync worker");
+}