diff --git a/cmd/gateway-s3.go b/cmd/gateway-s3.go
index 7c4c8aa9f..f2be3f269 100644
--- a/cmd/gateway-s3.go
+++ b/cmd/gateway-s3.go
@@ -449,7 +449,7 @@ func (l *s3Gateway) CopyObjectPart(srcBucket string, srcObject string, destBucke
 func fromMinioClientObjectPart(op minio.ObjectPart) PartInfo {
 	return PartInfo{
 		Size:         op.Size,
-		ETag:         op.ETag,
+		ETag:         canonicalizeETag(op.ETag),
 		LastModified: op.LastModified,
 		PartNumber:   op.PartNumber,
 	}