diff --git a/cluster_test.go b/cluster_test.go
index 076f4b67..2bf5d916 100644
--- a/cluster_test.go
+++ b/cluster_test.go
@@ -574,8 +574,8 @@ var _ = Describe("ClusterClient", func() {
 	Describe("ClusterClient failover", func() {
 		BeforeEach(func() {
 			opt = redisClusterOptions()
-			opt.MinRetryBackoff = 100 * time.Millisecond
-			opt.MaxRetryBackoff = 3 * time.Second
+			opt.MinRetryBackoff = 250 * time.Millisecond
+			opt.MaxRetryBackoff = time.Second
 			client = cluster.clusterClient(opt)
 
 			_ = client.ForEachSlave(func(slave *redis.Client) error {
diff --git a/command.go b/command.go
index 480a5ce1..7d45c3fa 100644
--- a/command.go
+++ b/command.go
@@ -10,6 +10,7 @@ import (
 	"github.com/go-redis/redis/internal"
 	"github.com/go-redis/redis/internal/pool"
 	"github.com/go-redis/redis/internal/proto"
+	"github.com/go-redis/redis/internal/util"
 )
 
 type Cmder interface {
@@ -436,7 +437,7 @@ func NewStringCmd(args ...interface{}) *StringCmd {
 }
 
 func (cmd *StringCmd) Val() string {
-	return internal.BytesToString(cmd.val)
+	return util.BytesToString(cmd.val)
 }
 
 func (cmd *StringCmd) Result() (string, error) {
diff --git a/commands.go b/commands.go
index 92a8b7a5..45bb0aed 100644
--- a/commands.go
+++ b/commands.go
@@ -1,6 +1,7 @@
 package redis
 
 import (
+	"errors"
 	"io"
 	"time"
 
@@ -1802,7 +1803,7 @@ func (c *cmdable) shutdown(modifier string) *StatusCmd {
 		}
 	} else {
 		// Server did not quit. String reply contains the reason.
-		cmd.err = internal.RedisError(cmd.val)
+		cmd.err = errors.New(cmd.val)
 		cmd.val = ""
 	}
 	return cmd
diff --git a/commands_test.go b/commands_test.go
index 524c3ac7..b173e0d4 100644
--- a/commands_test.go
+++ b/commands_test.go
@@ -10,7 +10,7 @@ import (
 	. "github.com/onsi/gomega"
 
 	"github.com/go-redis/redis"
-	"github.com/go-redis/redis/internal"
+	"github.com/go-redis/redis/internal/proto"
 )
 
 var _ = Describe("Commands", func() {
@@ -3000,7 +3000,7 @@ var _ = Describe("Commands", func() {
 				nil,
 			).Result()
 			Expect(err).NotTo(HaveOccurred())
-			Expect(vals).To(Equal([]interface{}{int64(12), internal.RedisError("error"), "abc"}))
+			Expect(vals).To(Equal([]interface{}{int64(12), proto.RedisError("error"), "abc"}))
 		})
 
 	})
diff --git a/internal/error.go b/internal/error.go
index c190f469..7b419577 100644
--- a/internal/error.go
+++ b/internal/error.go
@@ -4,14 +4,10 @@ import (
 	"io"
 	"net"
 	"strings"
+
+	"github.com/go-redis/redis/internal/proto"
 )
 
-const Nil = RedisError("redis: nil")
-
-type RedisError string
-
-func (e RedisError) Error() string { return string(e) }
-
 func IsRetryableError(err error, retryNetError bool) bool {
 	if IsNetworkError(err) {
 		return retryNetError
@@ -30,7 +26,7 @@ func IsRetryableError(err error, retryNetError bool) bool {
 }
 
 func IsRedisError(err error) bool {
-	_, ok := err.(RedisError)
+	_, ok := err.(proto.RedisError)
 	return ok
 }
 
diff --git a/internal/proto/reader.go b/internal/proto/reader.go
index e5ae8a03..d5d69535 100644
--- a/internal/proto/reader.go
+++ b/internal/proto/reader.go
@@ -6,7 +6,7 @@ import (
 	"io"
 	"strconv"
 
-	"github.com/go-redis/redis/internal"
+	"github.com/go-redis/redis/internal/util"
 )
 
 const bytesAllocLimit = 1024 * 1024 // 1mb
@@ -19,6 +19,16 @@ const (
 	ArrayReply  = '*'
 )
 
+//------------------------------------------------------------------------------
+
+const Nil = RedisError("redis: nil")
+
+type RedisError string
+
+func (e RedisError) Error() string { return string(e) }
+
+//------------------------------------------------------------------------------
+
 type MultiBulkParse func(*Reader, int64) (interface{}, error)
 
 type Reader struct {
@@ -66,7 +76,7 @@ func (r *Reader) ReadLine() ([]byte, error) {
 		return nil, fmt.Errorf("redis: reply is empty")
 	}
 	if isNilReply(line) {
-		return nil, internal.Nil
+		return nil, Nil
 	}
 	return line, nil
 }
@@ -83,7 +93,7 @@ func (r *Reader) ReadReply(m MultiBulkParse) (interface{}, error) {
 	case StatusReply:
 		return parseStatusValue(line), nil
 	case IntReply:
-		return parseInt(line[1:], 10, 64)
+		return util.ParseInt(line[1:], 10, 64)
 	case StringReply:
 		return r.readTmpBytesValue(line)
 	case ArrayReply:
@@ -105,7 +115,7 @@ func (r *Reader) ReadIntReply() (int64, error) {
 	case ErrorReply:
 		return 0, ParseErrorReply(line)
 	case IntReply:
-		return parseInt(line[1:], 10, 64)
+		return util.ParseInt(line[1:], 10, 64)
 	default:
 		return 0, fmt.Errorf("redis: can't parse int reply: %.100q", line)
 	}
@@ -151,7 +161,7 @@ func (r *Reader) ReadFloatReply() (float64, error) {
 	if err != nil {
 		return 0, err
 	}
-	return parseFloat(b, 64)
+	return util.ParseFloat(b, 64)
 }
 
 func (r *Reader) ReadArrayReply(m MultiBulkParse) (interface{}, error) {
@@ -221,7 +231,7 @@ func (r *Reader) ReadScanReply() ([]string, uint64, error) {
 
 func (r *Reader) readTmpBytesValue(line []byte) ([]byte, error) {
 	if isNilReply(line) {
-		return nil, internal.Nil
+		return nil, Nil
 	}
 
 	replyLen, err := strconv.Atoi(string(line[1:]))
@@ -241,7 +251,7 @@ func (r *Reader) ReadInt() (int64, error) {
 	if err != nil {
 		return 0, err
 	}
-	return parseInt(b, 10, 64)
+	return util.ParseInt(b, 10, 64)
 }
 
 func (r *Reader) ReadUint() (uint64, error) {
@@ -249,7 +259,7 @@ func (r *Reader) ReadUint() (uint64, error) {
 	if err != nil {
 		return 0, err
 	}
-	return parseUint(b, 10, 64)
+	return util.ParseUint(b, 10, 64)
 }
 
 // --------------------------------------------------------------------
@@ -303,7 +313,7 @@ func isNilReply(b []byte) bool {
 }
 
 func ParseErrorReply(line []byte) error {
-	return internal.RedisError(string(line[1:]))
+	return RedisError(string(line[1:]))
 }
 
 func parseStatusValue(line []byte) []byte {
@@ -312,23 +322,7 @@ func parseStatusValue(line []byte) []byte {
 
 func parseArrayLen(line []byte) (int64, error) {
 	if isNilReply(line) {
-		return 0, internal.Nil
+		return 0, Nil
 	}
-	return parseInt(line[1:], 10, 64)
-}
-
-func atoi(b []byte) (int, error) {
-	return strconv.Atoi(internal.BytesToString(b))
-}
-
-func parseInt(b []byte, base int, bitSize int) (int64, error) {
-	return strconv.ParseInt(internal.BytesToString(b), base, bitSize)
-}
-
-func parseUint(b []byte, base int, bitSize int) (uint64, error) {
-	return strconv.ParseUint(internal.BytesToString(b), base, bitSize)
-}
-
-func parseFloat(b []byte, bitSize int) (float64, error) {
-	return strconv.ParseFloat(internal.BytesToString(b), bitSize)
+	return util.ParseInt(line[1:], 10, 64)
 }
diff --git a/internal/proto/scan.go b/internal/proto/scan.go
index 0329ffd9..3bdb33f9 100644
--- a/internal/proto/scan.go
+++ b/internal/proto/scan.go
@@ -5,7 +5,7 @@ import (
 	"fmt"
 	"reflect"
 
-	"github.com/go-redis/redis/internal"
+	"github.com/go-redis/redis/internal/util"
 )
 
 func Scan(b []byte, v interface{}) error {
@@ -13,80 +13,80 @@ func Scan(b []byte, v interface{}) error {
 	case nil:
 		return fmt.Errorf("redis: Scan(nil)")
 	case *string:
-		*v = internal.BytesToString(b)
+		*v = util.BytesToString(b)
 		return nil
 	case *[]byte:
 		*v = b
 		return nil
 	case *int:
 		var err error
-		*v, err = atoi(b)
+		*v, err = util.Atoi(b)
 		return err
 	case *int8:
-		n, err := parseInt(b, 10, 8)
+		n, err := util.ParseInt(b, 10, 8)
 		if err != nil {
 			return err
 		}
 		*v = int8(n)
 		return nil
 	case *int16:
-		n, err := parseInt(b, 10, 16)
+		n, err := util.ParseInt(b, 10, 16)
 		if err != nil {
 			return err
 		}
 		*v = int16(n)
 		return nil
 	case *int32:
-		n, err := parseInt(b, 10, 32)
+		n, err := util.ParseInt(b, 10, 32)
 		if err != nil {
 			return err
 		}
 		*v = int32(n)
 		return nil
 	case *int64:
-		n, err := parseInt(b, 10, 64)
+		n, err := util.ParseInt(b, 10, 64)
 		if err != nil {
 			return err
 		}
 		*v = n
 		return nil
 	case *uint:
-		n, err := parseUint(b, 10, 64)
+		n, err := util.ParseUint(b, 10, 64)
 		if err != nil {
 			return err
 		}
 		*v = uint(n)
 		return nil
 	case *uint8:
-		n, err := parseUint(b, 10, 8)
+		n, err := util.ParseUint(b, 10, 8)
 		if err != nil {
 			return err
 		}
 		*v = uint8(n)
 		return nil
 	case *uint16:
-		n, err := parseUint(b, 10, 16)
+		n, err := util.ParseUint(b, 10, 16)
 		if err != nil {
 			return err
 		}
 		*v = uint16(n)
 		return nil
 	case *uint32:
-		n, err := parseUint(b, 10, 32)
+		n, err := util.ParseUint(b, 10, 32)
 		if err != nil {
 			return err
 		}
 		*v = uint32(n)
 		return nil
 	case *uint64:
-		n, err := parseUint(b, 10, 64)
+		n, err := util.ParseUint(b, 10, 64)
 		if err != nil {
 			return err
 		}
 		*v = n
 		return nil
 	case *float32:
-		n, err := parseFloat(b, 32)
+		n, err := util.ParseFloat(b, 32)
 		if err != nil {
 			return err
 		}
@@ -94,7 +94,7 @@ func Scan(b []byte, v interface{}) error {
 		return err
 	case *float64:
 		var err error
-		*v, err = parseFloat(b, 64)
+		*v, err = util.ParseFloat(b, 64)
 		return err
 	case *bool:
 		*v = len(b) == 1 && b[0] == '1'
@@ -120,7 +120,7 @@ func ScanSlice(data []string, slice interface{}) error {
 		return fmt.Errorf("redis: ScanSlice(non-slice %T)", slice)
 	}
 
-	next := internal.MakeSliceNextElemFunc(v)
+	next := makeSliceNextElemFunc(v)
 	for i, s := range data {
 		elem := next()
 		if err := Scan([]byte(s), elem.Addr().Interface()); err != nil {
@@ -131,3 +131,36 @@ func ScanSlice(data []string, slice interface{}) error {
 
 	return nil
 }
+
+func makeSliceNextElemFunc(v reflect.Value) func() reflect.Value {
+	elemType := v.Type().Elem()
+
+	if elemType.Kind() == reflect.Ptr {
+		elemType = elemType.Elem()
+		return func() reflect.Value {
+			if v.Len() < v.Cap() {
+				v.Set(v.Slice(0, v.Len()+1))
+				elem := v.Index(v.Len() - 1)
+				if elem.IsNil() {
+					elem.Set(reflect.New(elemType))
+				}
+				return elem.Elem()
+			}
+
+			elem := reflect.New(elemType)
+			v.Set(reflect.Append(v, elem))
+			return elem.Elem()
+		}
+	}
+
+	zero := reflect.Zero(elemType)
+	return func() reflect.Value {
+		if v.Len() < v.Cap() {
+			v.Set(v.Slice(0, v.Len()+1))
+			return v.Index(v.Len() - 1)
+		}
+
+		v.Set(reflect.Append(v, zero))
+		return v.Index(v.Len() - 1)
+	}
+}
diff --git a/internal/util.go b/internal/util.go
index 1ba9805f..ffd2353e 100644
--- a/internal/util.go
+++ b/internal/util.go
@@ -1,6 +1,6 @@
 package internal
 
-import "reflect"
+import "github.com/go-redis/redis/internal/util"
 
 func ToLower(s string) string {
 	if isLower(s) {
@@ -15,7 +15,7 @@ func ToLower(s string) string {
 		}
 		b[i] = c
 	}
-	return BytesToString(b)
+	return util.BytesToString(b)
 }
 
 func isLower(s string) bool {
@@ -27,36 +27,3 @@ func isLower(s string) bool {
 	}
 	return true
 }
-
-func MakeSliceNextElemFunc(v reflect.Value) func() reflect.Value {
-	elemType := v.Type().Elem()
-
-	if elemType.Kind() == reflect.Ptr {
-		elemType = elemType.Elem()
-		return func() reflect.Value {
-			if v.Len() < v.Cap() {
-				v.Set(v.Slice(0, v.Len()+1))
-				elem := v.Index(v.Len() - 1)
-				if elem.IsNil() {
-					elem.Set(reflect.New(elemType))
-				}
-				return elem.Elem()
-			}
-
-			elem := reflect.New(elemType)
-			v.Set(reflect.Append(v, elem))
-			return elem.Elem()
-		}
-	}
-
-	zero := reflect.Zero(elemType)
-	return func() reflect.Value {
-		if v.Len() < v.Cap() {
-			v.Set(v.Slice(0, v.Len()+1))
-			return v.Index(v.Len() - 1)
-		}
-
-		v.Set(reflect.Append(v, zero))
-		return v.Index(v.Len() - 1)
-	}
-}
diff --git a/internal/safe.go b/internal/util/safe.go
similarity index 82%
rename from internal/safe.go
rename to internal/util/safe.go
index dc5f4cc8..cd891833 100644
--- a/internal/safe.go
+++ b/internal/util/safe.go
@@ -1,6 +1,6 @@
 // +build appengine
 
-package internal
+package util
 
 func BytesToString(b []byte) string {
 	return string(b)
diff --git a/internal/util/strconv.go b/internal/util/strconv.go
new file mode 100644
index 00000000..db503380
--- /dev/null
+++ b/internal/util/strconv.go
@@ -0,0 +1,19 @@
+package util
+
+import "strconv"
+
+func Atoi(b []byte) (int, error) {
+	return strconv.Atoi(BytesToString(b))
+}
+
+func ParseInt(b []byte, base int, bitSize int) (int64, error) {
+	return strconv.ParseInt(BytesToString(b), base, bitSize)
+}
+
+func ParseUint(b []byte, base int, bitSize int) (uint64, error) {
+	return strconv.ParseUint(BytesToString(b), base, bitSize)
+}
+
+func ParseFloat(b []byte, bitSize int) (float64, error) {
+	return strconv.ParseFloat(BytesToString(b), bitSize)
+}
diff --git a/internal/unsafe.go b/internal/util/unsafe.go
similarity index 91%
rename from internal/unsafe.go
rename to internal/util/unsafe.go
index 3ae48c14..93a89c55 100644
--- a/internal/unsafe.go
+++ b/internal/util/unsafe.go
@@ -1,6 +1,6 @@
 // +build !appengine
 
-package internal
+package util
 
 import (
 	"unsafe"
diff --git a/parser.go b/parser.go
index e77efeeb..f0dc67f0 100644
--- a/parser.go
+++ b/parser.go
@@ -14,17 +14,23 @@ func sliceParser(rd *proto.Reader, n int64) (interface{}, error) {
 	vals := make([]interface{}, 0, n)
 	for i := int64(0); i < n; i++ {
 		v, err := rd.ReadReply(sliceParser)
-		if err == Nil {
-			vals = append(vals, nil)
-		} else if err != nil {
-			vals = append(vals, err)
-		} else {
-			switch vv := v.(type) {
-			case []byte:
-				vals = append(vals, string(vv))
-			default:
-				vals = append(vals, v)
+		if err != nil {
+			if err == Nil {
+				vals = append(vals, nil)
+				continue
 			}
+			if err, ok := err.(proto.RedisError); ok {
+				vals = append(vals, err)
+				continue
+			}
+			return nil, err
+		}
+
+		switch v := v.(type) {
+		case []byte:
+			vals = append(vals, string(v))
+		default:
+			vals = append(vals, v)
 		}
 	}
 	return vals, nil
diff --git a/redis.go b/redis.go
index cf402986..20f1ed1c 100644
--- a/redis.go
+++ b/redis.go
@@ -12,7 +12,7 @@ import (
 )
 
 // Nil reply redis returned when key does not exist.
-const Nil = internal.Nil
+const Nil = proto.Nil
 
 func init() {
 	SetLogger(log.New(os.Stderr, "redis: ", log.LstdFlags|log.Lshortfile))
diff --git a/tx.go b/tx.go
index 26c29bef..6a753b6a 100644
--- a/tx.go
+++ b/tx.go
@@ -1,12 +1,12 @@
 package redis
 
 import (
-	"github.com/go-redis/redis/internal"
 	"github.com/go-redis/redis/internal/pool"
+	"github.com/go-redis/redis/internal/proto"
 )
 
 // TxFailedErr transaction redis failed.
-const TxFailedErr = internal.RedisError("redis: transaction failed")
+const TxFailedErr = proto.RedisError("redis: transaction failed")
 
 // Tx implements Redis transactions as described in
 // http://redis.io/topics/transactions. It's NOT safe for concurrent use