diff --git a/bench_test.go b/bench_test.go
index 021dba96..85514066 100644
--- a/bench_test.go
+++ b/bench_test.go
@@ -188,7 +188,7 @@ func BenchmarkPipeline(b *testing.B) {
 
 	b.RunParallel(func(pb *testing.PB) {
 		for pb.Next() {
-			_, err := client.Pipelined(func(pipe *redis.Pipeline) error {
+			_, err := client.Pipelined(func(pipe redis.Pipeliner) error {
 				pipe.Set("key", "hello", 0)
 				pipe.Expire("key", time.Second)
 				return nil
diff --git a/cluster.go b/cluster.go
index 43cbf643..5c2e59ff 100644
--- a/cluster.go
+++ b/cluster.go
@@ -674,7 +674,7 @@ func (c *ClusterClient) reaper(idleCheckFrequency time.Duration) {
 	}
 }
 
-func (c *ClusterClient) Pipeline() *Pipeline {
+func (c *ClusterClient) Pipeline() Pipeliner {
 	pipe := Pipeline{
 		exec: c.pipelineExec,
 	}
@@ -683,7 +683,7 @@ func (c *ClusterClient) Pipeline() *Pipeline {
 	return &pipe
 }
 
-func (c *ClusterClient) Pipelined(fn func(*Pipeline) error) ([]Cmder, error) {
+func (c *ClusterClient) Pipelined(fn func(Pipeliner) error) ([]Cmder, error) {
 	return c.Pipeline().pipelined(fn)
 }
 
@@ -797,7 +797,7 @@ func (c *ClusterClient) checkMovedErr(cmd Cmder, failedCmds map[*clusterNode][]C
 }
 
 // TxPipeline acts like Pipeline, but wraps queued commands with MULTI/EXEC.
-func (c *ClusterClient) TxPipeline() *Pipeline {
+func (c *ClusterClient) TxPipeline() Pipeliner {
 	pipe := Pipeline{
 		exec: c.txPipelineExec,
 	}
@@ -806,7 +806,7 @@ func (c *ClusterClient) TxPipeline() *Pipeline {
 	return &pipe
 }
 
-func (c *ClusterClient) TxPipelined(fn func(*Pipeline) error) ([]Cmder, error) {
+func (c *ClusterClient) TxPipelined(fn func(Pipeliner) error) ([]Cmder, error) {
 	return c.TxPipeline().pipelined(fn)
 }
 
diff --git a/cluster_test.go b/cluster_test.go
index d9db8975..1e55be6e 100644
--- a/cluster_test.go
+++ b/cluster_test.go
@@ -347,7 +347,7 @@ var _ = Describe("ClusterClient", func() {
 						return err
 					}
 
-					_, err = tx.Pipelined(func(pipe *redis.Pipeline) error {
+					_, err = tx.Pipelined(func(pipe redis.Pipeliner) error {
 						pipe.Set(key, strconv.FormatInt(n+1, 10), 0)
 						return nil
 					})
@@ -449,7 +449,7 @@ var _ = Describe("ClusterClient", func() {
 
 			Describe("Pipeline", func() {
 				BeforeEach(func() {
-					pipe = client.Pipeline()
+					pipe = client.Pipeline().(*redis.Pipeline)
 				})
 
 				AfterEach(func() {
@@ -461,7 +461,7 @@ var _ = Describe("ClusterClient", func() {
 
 			Describe("TxPipeline", func() {
 				BeforeEach(func() {
-					pipe = client.TxPipeline()
+					pipe = client.TxPipeline().(*redis.Pipeline)
 				})
 
 				AfterEach(func() {
@@ -544,7 +544,7 @@ var _ = Describe("ClusterClient without nodes", func() {
 	})
 
 	It("pipeline returns an error", func() {
-		_, err := client.Pipelined(func(pipe *redis.Pipeline) error {
+		_, err := client.Pipelined(func(pipe redis.Pipeliner) error {
 			pipe.Ping()
 			return nil
 		})
@@ -571,7 +571,7 @@ var _ = Describe("ClusterClient without valid nodes", func() {
 	})
 
 	It("pipeline returns an error", func() {
-		_, err := client.Pipelined(func(pipe *redis.Pipeline) error {
+		_, err := client.Pipelined(func(pipe redis.Pipeliner) error {
 			pipe.Ping()
 			return nil
 		})
@@ -594,7 +594,7 @@ var _ = Describe("ClusterClient timeout", func() {
 		})
 
 		It("Pipeline timeouts", func() {
-			_, err := client.Pipelined(func(pipe *redis.Pipeline) error {
+			_, err := client.Pipelined(func(pipe redis.Pipeliner) error {
 				pipe.Ping()
 				return nil
 			})
@@ -612,7 +612,7 @@ var _ = Describe("ClusterClient timeout", func() {
 
 		It("Tx Pipeline timeouts", func() {
 			err := client.Watch(func(tx *redis.Tx) error {
-				_, err := tx.Pipelined(func(pipe *redis.Pipeline) error {
+				_, err := tx.Pipelined(func(pipe redis.Pipeliner) error {
 					pipe.Ping()
 					return nil
 				})
diff --git a/command.go b/command.go
index 543aeac1..33c11aaf 100644
--- a/command.go
+++ b/command.go
@@ -111,10 +111,7 @@ type baseCmd struct {
 }
 
 func (cmd *baseCmd) Err() error {
-	if cmd.err != nil {
-		return cmd.err
-	}
-	return nil
+	return cmd.err
 }
 
 func (cmd *baseCmd) args() []interface{} {
diff --git a/commands.go b/commands.go
index fb0e9105..a0984321 100644
--- a/commands.go
+++ b/commands.go
@@ -39,8 +39,8 @@ func formatSec(dur time.Duration) int64 {
 }
 
 type Cmdable interface {
-	Pipeline() *Pipeline
-	Pipelined(fn func(*Pipeline) error) ([]Cmder, error)
+	Pipeline() Pipeliner
+	Pipelined(fn func(Pipeliner) error) ([]Cmder, error)
 
 	Echo(message interface{}) *StringCmd
 	Ping() *StatusCmd
@@ -237,6 +237,15 @@ type Cmdable interface {
 	Command() *CommandsInfoCmd
 }
 
+type StatefulCmdable interface {
+	Auth(password string) *StatusCmd
+	Select(index int) *StatusCmd
+	ClientSetName(name string) *BoolCmd
+	ClientGetName() *StringCmd
+	ReadOnly() *StatusCmd
+	ReadWrite() *StatusCmd
+}
+
 var _ Cmdable = (*Client)(nil)
 var _ Cmdable = (*Tx)(nil)
 var _ Cmdable = (*Ring)(nil)
diff --git a/commands_test.go b/commands_test.go
index a1231334..3a0240dd 100644
--- a/commands_test.go
+++ b/commands_test.go
@@ -27,7 +27,7 @@ var _ = Describe("Commands", func() {
 	Describe("server", func() {
 
 		It("should Auth", func() {
-			_, err := client.Pipelined(func(pipe *redis.Pipeline) error {
+			_, err := client.Pipelined(func(pipe redis.Pipeliner) error {
 				pipe.Auth("password")
 				return nil
 			})
diff --git a/example_test.go b/example_test.go
index 6c3d6bdb..6453fd15 100644
--- a/example_test.go
+++ b/example_test.go
@@ -159,7 +159,7 @@ func ExampleClient_Scan() {
 
 func ExampleClient_Pipelined() {
 	var incr *redis.IntCmd
-	_, err := client.Pipelined(func(pipe *redis.Pipeline) error {
+	_, err := client.Pipelined(func(pipe redis.Pipeliner) error {
 		incr = pipe.Incr("pipelined_counter")
 		pipe.Expire("pipelined_counter", time.Hour)
 		return nil
@@ -187,7 +187,7 @@ func ExampleClient_Pipeline() {
 
 func ExampleClient_TxPipelined() {
 	var incr *redis.IntCmd
-	_, err := client.TxPipelined(func(pipe *redis.Pipeline) error {
+	_, err := client.TxPipelined(func(pipe redis.Pipeliner) error {
 		incr = pipe.Incr("tx_pipelined_counter")
 		pipe.Expire("tx_pipelined_counter", time.Hour)
 		return nil
@@ -226,7 +226,7 @@ func ExampleClient_Watch() {
 				return err
 			}
 
-			_, err = tx.Pipelined(func(pipe *redis.Pipeline) error {
+			_, err = tx.Pipelined(func(pipe redis.Pipeliner) error {
 				pipe.Set(key, strconv.FormatInt(n+1, 10), 0)
 				return nil
 			})
diff --git a/pipeline.go b/pipeline.go
index 9e3ba0e6..977f5eb3 100644
--- a/pipeline.go
+++ b/pipeline.go
@@ -9,6 +9,19 @@ import (
 
 type pipelineExecer func([]Cmder) error
 
+type Pipeliner interface {
+	Cmdable
+	StatefulCmdable
+	Process(cmd Cmder) error
+	Close() error
+	Discard() error
+	discard() error
+	Exec() ([]Cmder, error)
+	pipelined(fn func(Pipeliner) error) ([]Cmder, error)
+}
+
+var _ Pipeliner = (*Pipeline)(nil)
+
 // Pipeline implements pipelining as described in
 // http://redis.io/topics/pipelining. It's safe for concurrent use
 // by multiple goroutines.
@@ -78,7 +91,7 @@ func (c *Pipeline) Exec() ([]Cmder, error) {
 	return cmds, c.exec(cmds)
 }
 
-func (c *Pipeline) pipelined(fn func(*Pipeline) error) ([]Cmder, error) {
+func (c *Pipeline) pipelined(fn func(Pipeliner) error) ([]Cmder, error) {
 	if err := fn(c); err != nil {
 		return nil, err
 	}
@@ -86,3 +99,11 @@ func (c *Pipeline) pipelined(fn func(*Pipeline) error) ([]Cmder, error) {
 	_ = c.Close()
 	return cmds, err
 }
+
+func (c *Pipeline) Pipelined(fn func(Pipeliner) error) ([]Cmder, error) {
+	return c.pipelined(fn)
+}
+
+func (c *Pipeline) Pipeline() Pipeliner {
+	return c
+}
diff --git a/pipeline_test.go b/pipeline_test.go
index 563bb66b..706ff59a 100644
--- a/pipeline_test.go
+++ b/pipeline_test.go
@@ -22,7 +22,7 @@ var _ = Describe("pipelining", func() {
 
 	It("supports block style", func() {
 		var get *redis.StringCmd
-		cmds, err := client.Pipelined(func(pipe *redis.Pipeline) error {
+		cmds, err := client.Pipelined(func(pipe redis.Pipeliner) error {
 			get = pipe.Get("foo")
 			return nil
 		})
@@ -63,7 +63,7 @@ var _ = Describe("pipelining", func() {
 
 	Describe("Pipeline", func() {
 		BeforeEach(func() {
-			pipe = client.Pipeline()
+			pipe = client.Pipeline().(*redis.Pipeline)
 		})
 
 		assertPipeline()
diff --git a/pool_test.go b/pool_test.go
index 5363c400..9d33559b 100644
--- a/pool_test.go
+++ b/pool_test.go
@@ -39,7 +39,7 @@ var _ = Describe("pool", func() {
 			var ping *redis.StatusCmd
 
 			err := client.Watch(func(tx *redis.Tx) error {
-				cmds, err := tx.Pipelined(func(pipe *redis.Pipeline) error {
+				cmds, err := tx.Pipelined(func(pipe redis.Pipeliner) error {
 					ping = pipe.Ping()
 					return nil
 				})
diff --git a/race_test.go b/race_test.go
index 0ec6a140..439e5e29 100644
--- a/race_test.go
+++ b/race_test.go
@@ -193,7 +193,7 @@ var _ = Describe("races", func() {
 					num, err := strconv.ParseInt(val, 10, 64)
 					Expect(err).NotTo(HaveOccurred())
 
-					cmds, err := tx.Pipelined(func(pipe *redis.Pipeline) error {
+					cmds, err := tx.Pipelined(func(pipe redis.Pipeliner) error {
 						pipe.Set("key", strconv.FormatInt(num+1, 10), 0)
 						return nil
 					})
diff --git a/redis.go b/redis.go
index b71b9fc6..e81100c4 100644
--- a/redis.go
+++ b/redis.go
@@ -61,7 +61,7 @@ func (c *baseClient) initConn(cn *pool.Conn) error {
 
 	// Temp client for Auth and Select.
 	client := newClient(c.opt, pool.NewSingleConnPool(cn))
-	_, err := client.Pipelined(func(pipe *Pipeline) error {
+	_, err := client.Pipelined(func(pipe Pipeliner) error {
 		if c.opt.Password != "" {
 			pipe.Auth(c.opt.Password)
 		}
@@ -324,11 +324,11 @@ func (c *Client) PoolStats() *PoolStats {
 	}
 }
 
-func (c *Client) Pipelined(fn func(*Pipeline) error) ([]Cmder, error) {
+func (c *Client) Pipelined(fn func(Pipeliner) error) ([]Cmder, error) {
 	return c.Pipeline().pipelined(fn)
 }
 
-func (c *Client) Pipeline() *Pipeline {
+func (c *Client) Pipeline() Pipeliner {
 	pipe := Pipeline{
 		exec: c.pipelineExecer(c.pipelineProcessCmds),
 	}
@@ -337,7 +337,7 @@ func (c *Client) Pipeline() *Pipeline {
 	return &pipe
 }
 
-func (c *Client) TxPipelined(fn func(*Pipeline) error) ([]Cmder, error) {
+func (c *Client) TxPipelined(fn func(Pipeliner) error) ([]Cmder, error) {
 	return c.TxPipeline().pipelined(fn)
 }
 
diff --git a/redis_test.go b/redis_test.go
index 2847963f..a27e3bc1 100644
--- a/redis_test.go
+++ b/redis_test.go
@@ -68,7 +68,7 @@ var _ = Describe("Client", func() {
 
 	It("should close Tx without closing the client", func() {
 		err := client.Watch(func(tx *redis.Tx) error {
-			_, err := tx.Pipelined(func(pipe *redis.Pipeline) error {
+			_, err := tx.Pipelined(func(pipe redis.Pipeliner) error {
 				pipe.Ping()
 				return nil
 			})
@@ -232,7 +232,7 @@ var _ = Describe("Client timeout", func() {
 		})
 
 		It("Pipeline timeouts", func() {
-			_, err := client.Pipelined(func(pipe *redis.Pipeline) error {
+			_, err := client.Pipelined(func(pipe redis.Pipeliner) error {
 				pipe.Ping()
 				return nil
 			})
@@ -263,7 +263,7 @@ var _ = Describe("Client timeout", func() {
 
 		It("Tx Pipeline timeouts", func() {
 			err := client.Watch(func(tx *redis.Tx) error {
-				_, err := tx.Pipelined(func(pipe *redis.Pipeline) error {
+				_, err := tx.Pipelined(func(pipe redis.Pipeliner) error {
 					pipe.Ping()
 					return nil
 				})
diff --git a/ring.go b/ring.go
index d13a33b7..c190b284 100644
--- a/ring.go
+++ b/ring.go
@@ -381,7 +381,7 @@ func (c *Ring) Close() error {
 	return firstErr
 }
 
-func (c *Ring) Pipeline() *Pipeline {
+func (c *Ring) Pipeline() Pipeliner {
 	pipe := Pipeline{
 		exec: c.pipelineExec,
 	}
@@ -390,7 +390,7 @@ func (c *Ring) Pipeline() *Pipeline {
 	return &pipe
 }
 
-func (c *Ring) Pipelined(fn func(*Pipeline) error) ([]Cmder, error) {
+func (c *Ring) Pipelined(fn func(Pipeliner) error) ([]Cmder, error) {
 	return c.Pipeline().pipelined(fn)
 }
 
diff --git a/ring_test.go b/ring_test.go
index 21adab2b..a61ee96a 100644
--- a/ring_test.go
+++ b/ring_test.go
@@ -137,7 +137,7 @@ var _ = Describe("Redis Ring", func() {
 				keys = append(keys, string(key))
 			}
 
-			_, err := ring.Pipelined(func(pipe *redis.Pipeline) error {
+			_, err := ring.Pipelined(func(pipe redis.Pipeliner) error {
 				for _, key := range keys {
 					pipe.Set(key, "value", 0).Err()
 				}
@@ -153,7 +153,7 @@ var _ = Describe("Redis Ring", func() {
 		})
 
 		It("supports hash tags", func() {
-			_, err := ring.Pipelined(func(pipe *redis.Pipeline) error {
+			_, err := ring.Pipelined(func(pipe redis.Pipeliner) error {
 				for i := 0; i < 100; i++ {
 					pipe.Set(fmt.Sprintf("key%d{tag}", i), "value", 0).Err()
 				}
@@ -184,7 +184,7 @@ var _ = Describe("empty Redis Ring", func() {
 	})
 
 	It("pipeline returns an error", func() {
-		_, err := ring.Pipelined(func(pipe *redis.Pipeline) error {
+		_, err := ring.Pipelined(func(pipe redis.Pipeliner) error {
 			pipe.Ping()
 			return nil
 		})
diff --git a/tx.go b/tx.go
index 762bddc9..21c5c70f 100644
--- a/tx.go
+++ b/tx.go
@@ -76,7 +76,7 @@ func (c *Tx) Unwatch(keys ...string) *StatusCmd {
 	return cmd
 }
 
-func (c *Tx) Pipeline() *Pipeline {
+func (c *Tx) Pipeline() Pipeliner {
 	pipe := Pipeline{
 		exec: c.pipelineExecer(c.txPipelineProcessCmds),
 	}
@@ -94,6 +94,6 @@ func (c *Tx) Pipeline() *Pipeline {
 // Exec always returns list of commands. If transaction fails
 // TxFailedErr is returned. Otherwise Exec returns error of the first
 // failed command or nil.
-func (c *Tx) Pipelined(fn func(*Pipeline) error) ([]Cmder, error) {
+func (c *Tx) Pipelined(fn func(Pipeliner) error) ([]Cmder, error) {
 	return c.Pipeline().pipelined(fn)
 }
diff --git a/tx_test.go b/tx_test.go
index 583ea057..83b12e1f 100644
--- a/tx_test.go
+++ b/tx_test.go
@@ -33,7 +33,7 @@ var _ = Describe("Tx", func() {
 					return err
 				}
 
-				_, err = tx.Pipelined(func(pipe *redis.Pipeline) error {
+				_, err = tx.Pipelined(func(pipe redis.Pipeliner) error {
 					pipe.Set(key, strconv.FormatInt(n+1, 10), 0)
 					return nil
 				})
@@ -65,7 +65,7 @@ var _ = Describe("Tx", func() {
 
 	It("should discard", func() {
 		err := client.Watch(func(tx *redis.Tx) error {
-			cmds, err := tx.Pipelined(func(pipe *redis.Pipeline) error {
+			cmds, err := tx.Pipelined(func(pipe redis.Pipeliner) error {
 				pipe.Set("key1", "hello1", 0)
 				pipe.Discard()
 				pipe.Set("key2", "hello2", 0)
@@ -88,7 +88,7 @@ var _ = Describe("Tx", func() {
 
 	It("returns an error when there are no commands", func() {
 		err := client.Watch(func(tx *redis.Tx) error {
-			_, err := tx.Pipelined(func(*redis.Pipeline) error { return nil })
+			_, err := tx.Pipelined(func(redis.Pipeliner) error { return nil })
 			return err
 		})
 		Expect(err).To(MatchError("redis: pipeline is empty"))
@@ -102,7 +102,7 @@ var _ = Describe("Tx", func() {
 		const N = 20000
 
 		err := client.Watch(func(tx *redis.Tx) error {
-			cmds, err := tx.Pipelined(func(pipe *redis.Pipeline) error {
+			cmds, err := tx.Pipelined(func(pipe redis.Pipeliner) error {
 				for i := 0; i < N; i++ {
 					pipe.Incr("key")
 				}
@@ -133,7 +133,7 @@ var _ = Describe("Tx", func() {
 
 		do := func() error {
 			err := client.Watch(func(tx *redis.Tx) error {
-				_, err := tx.Pipelined(func(pipe *redis.Pipeline) error {
+				_, err := tx.Pipelined(func(pipe redis.Pipeliner) error {
 					pipe.Ping()
 					return nil
 				})