diff --git a/tests/comp_bytes.js b/tests/comp_bytes.js
index ab088ecf3..17dacee92 100644
--- a/tests/comp_bytes.js
+++ b/tests/comp_bytes.js
@@ -1,39 +1,43 @@
 var tape = require("tape");
 
-class CustomBuffer extends Buffer {
-    static toCustom(b) {
-        b._isCustom = true;
-        return b;
-    }
-
-    static isCustom(b) {
-        return !!b._isCustom;
-    }
-
-    static from(...args) {
-        return CustomBuffer.toCustom(Buffer.from(...args));
-    }
-
-    static alloc(...args) {
-        return CustomBuffer.toCustom(Buffer.alloc(...args));
-    }
-
-    static allocUnsafe(...args) {
-        return CustomBuffer.toCustom(Buffer.allocUnsafe(...args));
-    }
-
-    static allocUnsafeSlow(...args) {
-        return CustomBuffer.toCustom(Buffer.allocUnsafeSlow(...args));
-    }
-
-    slice(...args) {
-        return CustomBuffer.toCustom(super.slice(...args));
-    }
+var protobuf = require("..");
+
+// extends Buffer
+(CustomBuffer.prototype = Object.create(Buffer.prototype)).constructor = CustomBuffer;
+
+function CustomBuffer() {
+    Buffer.call(this);
+}
+
+CustomBuffer.isBuffer = Buffer.isBuffer.bind(Buffer);
+
+CustomBuffer.toCustom = function (b) {
+    b._isCustom = true;
+    return b;
+}
+
+CustomBuffer.isCustom = function (b) {
+    return !!b._isCustom;
+}
+
+CustomBuffer.from = function (...args) {
+    return CustomBuffer.toCustom(Buffer.from(...args));
+}
+
+CustomBuffer.allow = function (...args) {
+    return CustomBuffer.toCustom(Buffer.alloc(...args));
+}
+
+CustomBuffer.allocUnsafe = function (...args) {
+    return CustomBuffer.toCustom(Buffer.allocUnsafe(...args));
+}
+
+CustomBuffer.prototype.slice = function (...args) {
+    return CustomBuffer.toCustom(this.slice(...args));
 }
 
 tape.test("configure a custom encoder/decoder for bytes", function(test) {
 
-    var protobuf = require("..");
     var oldBuffer = protobuf.util.Buffer;
 
     protobuf.util.Buffer = CustomBuffer;