diff --git a/js/experimental/runtime/kernel/writer.js b/js/experimental/runtime/kernel/writer.js
index 73f852e6f6..8b830105ef 100644
--- a/js/experimental/runtime/kernel/writer.js
+++ b/js/experimental/runtime/kernel/writer.js
@@ -411,7 +411,8 @@ class Writer {
     this.writeTag(fieldNumber, WireType.DELIMITED);
     const array = encoderFunction(value);
     this.writeUnsignedVarint32_(array.length);
-    this.writeRaw_(array.buffer);
+    this.closeAndStartNewBuffer_();
+    this.blocks_.push(array);
   }
 
   /**