diff --git a/engine/env_test.go b/engine/env_test.go
index 39669d6780..104b0db5bf 100644
--- a/engine/env_test.go
+++ b/engine/env_test.go
@@ -1,7 +1,10 @@
 package engine
 
 import (
+	"bytes"
 	"testing"
+
+	"github.com/dotcloud/docker/pkg/testutils"
 )
 
 func TestEnvLenZero(t *testing.T) {
@@ -143,3 +146,126 @@ func TestMultiMap(t *testing.T) {
 		t.Fatalf("%#v", v)
 	}
 }
+
+func testMap(l int) [][2]string {
+	res := make([][2]string, l)
+	for i := 0; i < l; i++ {
+		t := [2]string{testutils.RandomString(5), testutils.RandomString(20)}
+		res[i] = t
+	}
+	return res
+}
+
+func BenchmarkSet(b *testing.B) {
+	fix := testMap(100)
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		env := &Env{}
+		for _, kv := range fix {
+			env.Set(kv[0], kv[1])
+		}
+	}
+}
+
+func BenchmarkSetJson(b *testing.B) {
+	fix := testMap(100)
+	type X struct {
+		f string
+	}
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		env := &Env{}
+		for _, kv := range fix {
+			if err := env.SetJson(kv[0], X{kv[1]}); err != nil {
+				b.Fatal(err)
+			}
+		}
+	}
+}
+
+func BenchmarkGet(b *testing.B) {
+	fix := testMap(100)
+	env := &Env{}
+	for _, kv := range fix {
+		env.Set(kv[0], kv[1])
+	}
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		for _, kv := range fix {
+			env.Get(kv[0])
+		}
+	}
+}
+
+func BenchmarkGetJson(b *testing.B) {
+	fix := testMap(100)
+	env := &Env{}
+	type X struct {
+		f string
+	}
+	for _, kv := range fix {
+		env.SetJson(kv[0], X{kv[1]})
+	}
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		for _, kv := range fix {
+			if err := env.GetJson(kv[0], &X{}); err != nil {
+				b.Fatal(err)
+			}
+		}
+	}
+}
+
+func BenchmarkEncode(b *testing.B) {
+	fix := testMap(100)
+	env := &Env{}
+	type X struct {
+		f string
+	}
+	// half a json
+	for i, kv := range fix {
+		if i%2 != 0 {
+			if err := env.SetJson(kv[0], X{kv[1]}); err != nil {
+				b.Fatal(err)
+			}
+			continue
+		}
+		env.Set(kv[0], kv[1])
+	}
+	var writer bytes.Buffer
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		env.Encode(&writer)
+		writer.Reset()
+	}
+}
+
+func BenchmarkDecode(b *testing.B) {
+	fix := testMap(100)
+	env := &Env{}
+	type X struct {
+		f string
+	}
+	// half a json
+	for i, kv := range fix {
+		if i%2 != 0 {
+			if err := env.SetJson(kv[0], X{kv[1]}); err != nil {
+				b.Fatal(err)
+			}
+			continue
+		}
+		env.Set(kv[0], kv[1])
+	}
+	var writer bytes.Buffer
+	env.Encode(&writer)
+	denv := &Env{}
+	reader := bytes.NewReader(writer.Bytes())
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		err := denv.Decode(reader)
+		if err != nil {
+			b.Fatal(err)
+		}
+		reader.Seek(0, 0)
+	}
+}
diff --git a/pkg/testutils/testutils.go b/pkg/testutils/testutils.go
index 4655e5844d..9c664ff253 100644
--- a/pkg/testutils/testutils.go
+++ b/pkg/testutils/testutils.go
@@ -1,10 +1,15 @@
 package testutils
 
 import (
+	"math/rand"
 	"testing"
 	"time"
 )
 
+const chars = "abcdefghijklmnopqrstuvwxyz" +
+	"ABCDEFGHIJKLMNOPQRSTUVWXYZ" +
+	"~!@#$%^&*()-_+={}[]\\|<,>.?/\"';:` "
+
 // Timeout calls f and waits for 100ms for it to complete.
 // If it doesn't, it causes the tests to fail.
 // t must be a valid testing context.
@@ -21,3 +26,12 @@ func Timeout(t *testing.T, f func()) {
 	case <-onDone:
 	}
 }
+
+// RandomString returns random string of specified length
+func RandomString(length int) string {
+	res := make([]byte, length)
+	for i := 0; i < length; i++ {
+		res[i] = chars[rand.Intn(len(chars))]
+	}
+	return string(res)
+}