diff --git a/uploader/multipart/multipart.go b/uploader/multipart/multipart.go
index 6fc6031..531b83f 100644
--- a/uploader/multipart/multipart.go
+++ b/uploader/multipart/multipart.go
@@ -107,7 +107,7 @@ func NewReader(r io.Reader, boundary string) *Reader {
 // underlying Reader once an error has been seen. (the io.Reader
 // interface's contract promises nothing about the return values of
 // Read calls after an error, yet this package does do multiple Reads
-// after error)
+// after error).
 type stickyErrorReader struct {
 	r   io.Reader
 	err error
@@ -142,11 +142,11 @@ func newPart(mr *Reader, rawPart bool) (*Part, error) {
 	return bp, nil
 }
 
-func (bp *Part) populateHeaders() error {
-	r := textproto.NewReader(bp.mr.bufReader)
+func (p *Part) populateHeaders() error {
+	r := textproto.NewReader(p.mr.bufReader)
 	header, err := r.ReadMIMEHeader()
 	if err == nil {
-		bp.Header = header
+		p.Header = header
 	}
 	return err
 }
@@ -278,7 +278,7 @@ func matchAfterPrefix(buf, prefix []byte, readErr error) int {
 }
 
 func (p *Part) Close() error {
-	io.Copy(io.Discard, p)
+	_, _ = io.Copy(io.Discard, p)
 	return nil
 }
 
@@ -378,37 +378,37 @@ func (r *Reader) nextPart(rawPart bool) (*Part, error) {
 
 // isFinalBoundary reports whether line is the final boundary line
 // indicating that all parts are over.
-// It matches `^--boundary--[ \t]*(\r\n)?$`
-func (mr *Reader) isFinalBoundary(line []byte) bool {
-	if !bytes.HasPrefix(line, mr.dashBoundaryDash) {
+// It matches `^--boundary--[ \t]*(\r\n)?$`.
+func (r *Reader) isFinalBoundary(line []byte) bool {
+	if !bytes.HasPrefix(line, r.dashBoundaryDash) {
 		return false
 	}
-	rest := line[len(mr.dashBoundaryDash):]
+	rest := line[len(r.dashBoundaryDash):]
 	rest = skipLWSPChar(rest)
-	return len(rest) == 0 || bytes.Equal(rest, mr.nl)
+	return len(rest) == 0 || bytes.Equal(rest, r.nl)
 }
 
-func (mr *Reader) isBoundaryDelimiterLine(line []byte) (ret bool) {
+func (r *Reader) isBoundaryDelimiterLine(line []byte) (ret bool) {
 	// https://tools.ietf.org/html/rfc2046#section-5.1
 	//   The boundary delimiter line is then defined as a line
 	//   consisting entirely of two hyphen characters ("-",
 	//   decimal value 45) followed by the boundary parameter
 	//   value from the Content-Type header field, optional linear
 	//   whitespace, and a terminating CRLF.
-	if !bytes.HasPrefix(line, mr.dashBoundary) {
+	if !bytes.HasPrefix(line, r.dashBoundary) {
 		return false
 	}
-	rest := line[len(mr.dashBoundary):]
+	rest := line[len(r.dashBoundary):]
 	rest = skipLWSPChar(rest)
 
 	// On the first part, see our lines are ending in \n instead of \r\n
 	// and switch into that mode if so. This is a violation of the spec,
 	// but occurs in practice.
-	if mr.partsRead == 0 && len(rest) == 1 && rest[0] == '\n' {
-		mr.nl = mr.nl[1:]
-		mr.nlDashBoundary = mr.nlDashBoundary[1:]
+	if r.partsRead == 0 && len(rest) == 1 && rest[0] == '\n' {
+		r.nl = r.nl[1:]
+		r.nlDashBoundary = r.nlDashBoundary[1:]
 	}
-	return bytes.Equal(rest, mr.nl)
+	return bytes.Equal(rest, r.nl)
 }
 
 // skipLWSPChar returns b with leading spaces and tabs removed.