diff --git a/lib/utils/serialize.js b/lib/utils/serialize.js
index a4beea05f3..58037f931a 100644
--- a/lib/utils/serialize.js
+++ b/lib/utils/serialize.js
@@ -47,7 +47,7 @@ class BinaryWriter {
         this.write_buffer(Buffer.from(new bn_js_1.default(value).toArray('le', 16)));
     }
     write_buffer(buffer) {
-        this.buf = Buffer.concat([this.buf.subarray(0, this.length), buffer, Buffer.alloc(INITIAL_LENGTH)]);
+        this.buf = Buffer.concat([Buffer.from(this.buf.subarray(0, this.length)), buffer, Buffer.alloc(INITIAL_LENGTH)]);
         this.length += buffer.length;
     }
     write_string(str) {
diff --git a/src.ts/utils/serialize.ts b/src.ts/utils/serialize.ts
index 0e0cb2612f..9cc7d5744c 100644
--- a/src.ts/utils/serialize.ts
+++ b/src.ts/utils/serialize.ts
@@ -57,7 +57,7 @@ export class BinaryWriter {
     }
 
     private write_buffer(buffer: Buffer) {
-        this.buf = Buffer.concat([this.buf.subarray(0, this.length), buffer, Buffer.alloc(INITIAL_LENGTH)]);
+        this.buf = Buffer.concat([Buffer.from(this.buf.subarray(0, this.length)), buffer, Buffer.alloc(INITIAL_LENGTH)]);
         this.length += buffer.length;
     }