diff --git a/src/cmd/link/internal/ld/lib.go b/src/cmd/link/internal/ld/lib.go
index a1413820c7..709790bc3d 100644
--- a/src/cmd/link/internal/ld/lib.go
+++ b/src/cmd/link/internal/ld/lib.go
@@ -758,7 +758,7 @@ func genhash(ctxt *Link, lib *Library) {
 		Errorf(nil, "%s: error reading package data: %v", lib.File, err)
 		return
 	}
-	firstEOL := bytes.Index(pkgDefBytes, []byte("\n"))
+	firstEOL := bytes.IndexByte(pkgDefBytes, '\n')
 	if firstEOL < 0 {
 		Errorf(nil, "cannot parse package data of %s for hash generation, no newline found", lib.File)
 		return
diff --git a/src/crypto/tls/handshake_client_test.go b/src/crypto/tls/handshake_client_test.go
index eaef8aa7a1..cc3ab714a6 100644
--- a/src/crypto/tls/handshake_client_test.go
+++ b/src/crypto/tls/handshake_client_test.go
@@ -85,7 +85,7 @@ func (o *opensslOutputSink) Write(data []byte) (n int, err error) {
 	o.all = append(o.all, data...)
 
 	for {
-		i := bytes.Index(o.line, []byte{'\n'})
+		i := bytes.IndexByte(o.line, '\n')
 		if i < 0 {
 			break
 		}
diff --git a/src/encoding/json/decode_test.go b/src/encoding/json/decode_test.go
index bd38ddd319..5a72f3a7c6 100644
--- a/src/encoding/json/decode_test.go
+++ b/src/encoding/json/decode_test.go
@@ -88,7 +88,7 @@ func (u unmarshalerText) MarshalText() ([]byte, error) {
 }
 
 func (u *unmarshalerText) UnmarshalText(b []byte) error {
-	pos := bytes.Index(b, []byte(":"))
+	pos := bytes.IndexByte(b, ':')
 	if pos == -1 {
 		return errors.New("missing separator")
 	}
diff --git a/src/encoding/pem/pem.go b/src/encoding/pem/pem.go
index 5e1ab90cff..887647b570 100644
--- a/src/encoding/pem/pem.go
+++ b/src/encoding/pem/pem.go
@@ -36,7 +36,7 @@ type Block struct {
 // bytes) is also returned and this will always be smaller than the original
 // argument.
 func getLine(data []byte) (line, rest []byte) {
-	i := bytes.Index(data, []byte{'\n'})
+	i := bytes.IndexByte(data, '\n')
 	var j int
 	if i < 0 {
 		i = len(data)
@@ -106,7 +106,7 @@ func Decode(data []byte) (p *Block, rest []byte) {
 		}
 		line, next := getLine(rest)
 
-		i := bytes.Index(line, []byte{':'})
+		i := bytes.IndexByte(line, ':')
 		if i == -1 {
 			break
 		}