diff --git a/lib/buffer.js b/lib/buffer.js
index 874227f0d44051..a818f41a26ed5b 100644
--- a/lib/buffer.js
+++ b/lib/buffer.js
@@ -257,7 +257,7 @@ function _copyActual(source, target, targetStart, sourceStart, sourceEnd) {
   if (nb > sourceLen)
     nb = sourceLen;
 
-  if (sourceStart !== 0 || sourceEnd !== source.length)
+  if (sourceStart !== 0 || sourceEnd < source.length)
     source = new Uint8Array(source.buffer, source.byteOffset + sourceStart, nb);
 
   target.set(source, targetStart);