diff --git a/src/cid.js b/src/cid.js
index cbb5fd80..4736898f 100644
--- a/src/cid.js
+++ b/src/cid.js
@@ -87,19 +87,6 @@ export class CID {
     // Circular reference
     /** @readonly */
     this.asCID = this
-
-    // Configure private properties
-    Object.defineProperties(this, {
-      byteOffset: hidden,
-      byteLength: hidden,
-
-      code: readonly,
-      version: readonly,
-      multihash: readonly,
-      bytes: readonly,
-
-      asCID: hidden
-    })
   }
 
   /**
@@ -568,5 +555,3 @@ const encodeCID = (version, code, multihash) => {
 }
 
 const cidSymbol = Symbol.for('@ipld/js-cid/CID')
-const readonly = { writable: false, configurable: false, enumerable: true }
-const hidden = { writable: false, enumerable: false, configurable: false }
diff --git a/test/test-cid.spec.js b/test/test-cid.spec.js
index 5bdd3b1d..6de0f6c5 100644
--- a/test/test-cid.spec.js
+++ b/test/test-cid.spec.js
@@ -696,4 +696,16 @@ describe('CID', () => {
     const encoded = varint.encodeTo(2, new Uint8Array(32))
     assert.throws(() => CID.decode(encoded), 'Invalid CID version 2')
   })
+
+  it('CID can be moved across JS realms', async () => {
+    const cid = CID.parse('bafybeif2pall7dybz7vecqka3zo24irdwabwdi4wc55jznaq75q7eaavvu')
+    const { port1: sender, port2: receiver } = new MessageChannel()
+    sender.postMessage(cid)
+    const cid2 = await new Promise((resolve) => {
+      receiver.onmessage = (event) => { resolve(event.data) }
+    })
+    assert.strictEqual(cid2.asCID, cid2)
+    sender.close()
+    receiver.close()
+  })
 })