diff --git a/lib/core/request.js b/lib/core/request.js
index 377bf31984b..c44cd0891f5 100644
--- a/lib/core/request.js
+++ b/lib/core/request.js
@@ -10,6 +10,7 @@ const {
   isValidHeaderValue,
   isStream,
   destroy,
+  isBuffer,
   isFormDataLike,
   isIterable,
   isBlobLike,
@@ -111,7 +112,7 @@ class Request {
         }
       }
       this.body.on('error', this.errorHandler)
-    } else if (Buffer.isBuffer(body)) {
+    } else if (isBuffer(body)) {
       this.body = body.byteLength ? body : null
     } else if (ArrayBuffer.isView(body)) {
       this.body = body.buffer.byteLength ? Buffer.from(body.buffer, body.byteOffset, body.byteLength) : null