diff --git a/boolean_test.go b/boolean_test.go
index 766989a..e88c2f7 100644
--- a/boolean_test.go
+++ b/boolean_test.go
@@ -4,13 +4,13 @@ import (
 	"reflect"
 	"testing"
 
-	"github.com/stretchr/testify/require"
-
 	"github.com/neotoolkit/faker"
 )
 
 func TestBoolean_Boolean(t *testing.T) {
 	f := faker.NewFaker().Boolean()
 
-	require.Equal(t, "bool", reflect.TypeOf(f.Boolean()).String())
+	if reflect.TypeOf(f.Boolean()).String() != "bool" {
+		t.Fatal("Boolean type must be bool")
+	}
 }
diff --git a/faker_test.go b/faker_test.go
index d47328e..e09d949 100644
--- a/faker_test.go
+++ b/faker_test.go
@@ -4,8 +4,6 @@ import (
 	"fmt"
 	"testing"
 
-	"github.com/stretchr/testify/require"
-
 	"github.com/neotoolkit/faker"
 )
 
@@ -33,9 +31,19 @@ func TestIntBetween(t *testing.T) {
 		t.Run(tc.name, func(t *testing.T) {
 			value := f.IntBetween(tc.min, tc.max)
 
-			require.Equal(t, fmt.Sprintf("%T", value), "int")
-			require.True(t, value >= tc.min)
-			require.True(t, value <= tc.max)
+			valueType := fmt.Sprintf("%T", value)
+
+			if valueType != "int" {
+				t.Fatalf("value type want int, got %T", value)
+			}
+
+			if value < tc.min {
+				t.Fatalf("value must be less %d", tc.min)
+			}
+
+			if value > tc.max {
+				t.Fatalf("value must be greater %d", tc.max)
+			}
 		})
 	}
 }
@@ -156,7 +164,9 @@ func TestByName(t *testing.T) {
 			f := faker.NewFaker()
 			got := f.ByName(tc.faker)
 
-			require.True(t, got != nil)
+			if nil == got {
+				t.Fatal("faker by name is nil")
+			}
 		})
 	}
 }
diff --git a/go.mod b/go.mod
index b67c9c9..5b9a5b1 100644
--- a/go.mod
+++ b/go.mod
@@ -1,14 +1,3 @@
 module github.com/neotoolkit/faker
 
-go 1.17
-
-require (
-	github.com/google/uuid v1.3.0
-	github.com/stretchr/testify v1.7.2
-)
-
-require (
-	github.com/davecgh/go-spew v1.1.0 // indirect
-	github.com/pmezard/go-difflib v1.0.0 // indirect
-	gopkg.in/yaml.v3 v3.0.1 // indirect
-)
+go 1.18
diff --git a/go.sum b/go.sum
index c48c554..e69de29 100644
--- a/go.sum
+++ b/go.sum
@@ -1,13 +0,0 @@
-github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8=
-github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
-github.com/google/uuid v1.3.0 h1:t6JiXgmwXMjEs8VusXIJk2BXHsn+wx8BZdTaoZ5fu7I=
-github.com/google/uuid v1.3.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
-github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
-github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
-github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
-github.com/stretchr/testify v1.7.2 h1:4jaiDzPyXQvSd7D0EjG45355tLlV3VOECpq10pLC+8s=
-github.com/stretchr/testify v1.7.2/go.mod h1:R6va5+xMeoiuVRoj+gSkQ7d3FALtqAAGI1FQKckRals=
-gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
-gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
-gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
-gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
diff --git a/internet_test.go b/internet_test.go
index ccb0777..eea0588 100644
--- a/internet_test.go
+++ b/internet_test.go
@@ -1,11 +1,8 @@
 package faker_test
 
 import (
-	"strings"
 	"testing"
 
-	"github.com/stretchr/testify/require"
-
 	"github.com/neotoolkit/faker"
 )
 
@@ -13,27 +10,34 @@ func TestUsername(t *testing.T) {
 	i := faker.NewFaker().Internet()
 	username := i.Username()
 
-	require.Equal(t, true, len(username) > 0)
-	require.Equal(t, false, strings.Contains(username, " "))
+	if len(username) == 0 {
+		t.Fatal("username is empty")
+	}
 }
 
 func TestGTLD(t *testing.T) {
 	i := faker.NewFaker().Internet()
 	gTLD := i.GTLD()
 
-	require.True(t, len(gTLD) > 0)
+	if len(gTLD) == 0 {
+		t.Fatal("gTLD is empty")
+	}
 }
 
 func TestDomain(t *testing.T) {
 	i := faker.NewFaker().Internet()
 	d := i.Domain()
 
-	require.True(t, len(d) > 0)
+	if len(d) == 0 {
+		t.Fatal("domain is empty")
+	}
 }
 
 func TestEmail(t *testing.T) {
 	i := faker.NewFaker().Internet()
 	e := i.Email()
 
-	require.True(t, len(e) > 0)
+	if len(e) == 0 {
+		t.Fatal("domain is empty")
+	}
 }
diff --git a/person_test.go b/person_test.go
index 5b2c3e0..9089d92 100644
--- a/person_test.go
+++ b/person_test.go
@@ -4,8 +4,6 @@ import (
 	"strings"
 	"testing"
 
-	"github.com/stretchr/testify/require"
-
 	"github.com/neotoolkit/faker"
 )
 
@@ -13,7 +11,9 @@ func TestPerson_FirstName(t *testing.T) {
 	f := faker.NewFaker()
 	firstName := f.Person().FirstName()
 
-	require.True(t, len(firstName) > 0)
+	if len(firstName) == 0 {
+		t.Fatal("firstName is empty")
+	}
 }
 
 func TestPerson_LastName(t *testing.T) {
@@ -21,14 +21,18 @@ func TestPerson_LastName(t *testing.T) {
 	p := f.Person()
 	lastName := p.LastName()
 
-	require.True(t, len(lastName) > 0)
+	if len(lastName) == 0 {
+		t.Fatal("lastName is empty")
+	}
 }
 
 func TestPerson_FirstNameMale(t *testing.T) {
 	f := faker.NewFaker()
 	firstNameMale := f.Person().FirstNameMale()
 
-	require.True(t, len(firstNameMale) > 0)
+	if len(firstNameMale) == 0 {
+		t.Fatal("firstNameMale is empty")
+	}
 }
 
 func TestPerson_FirstNameFemale(t *testing.T) {
@@ -36,7 +40,9 @@ func TestPerson_FirstNameFemale(t *testing.T) {
 	p := f.Person()
 	firstNameFemale := p.FirstNameFemale()
 
-	require.True(t, len(firstNameFemale) > 0)
+	if len(firstNameFemale) == 0 {
+		t.Fatal("firstNameFemale is empty")
+	}
 }
 
 func TestPerson_Name(t *testing.T) {
@@ -44,10 +50,21 @@ func TestPerson_Name(t *testing.T) {
 	p := f.Person()
 	name := p.Name()
 
-	require.True(t, len(name) > 0)
-	require.False(t, strings.Contains(name, "{{FirstNameMale}}"))
-	require.False(t, strings.Contains(name, "{{FirstNameFemale}}"))
-	require.False(t, strings.Contains(name, "{{LastName}}"))
+	if len(name) == 0 {
+		t.Fatal("name is empty")
+	}
+
+	if strings.Contains(name, "{{FirstNameMale}}") {
+		t.Fatal("name is format")
+	}
+
+	if strings.Contains(name, "{{FirstNameFemale}}") {
+		t.Fatal("name is format")
+	}
+
+	if strings.Contains(name, "{{LastName}}") {
+		t.Fatal("name is format")
+	}
 }
 
 func TestPerson_NameMale(t *testing.T) {
@@ -55,7 +72,9 @@ func TestPerson_NameMale(t *testing.T) {
 	p := f.Person()
 	nameMale := p.NameMale()
 
-	require.True(t, len(nameMale) > 0)
+	if len(nameMale) == 0 {
+		t.Fatal("nameMale is empty")
+	}
 }
 
 func TestPerson_NameFemale(t *testing.T) {
@@ -63,7 +82,9 @@ func TestPerson_NameFemale(t *testing.T) {
 	p := f.Person()
 	nameFemale := p.NameFemale()
 
-	require.True(t, len(nameFemale) > 0)
+	if len(nameFemale) == 0 {
+		t.Fatal("nameFemale is empty")
+	}
 }
 
 func TestPerson_Gender(t *testing.T) {
@@ -71,7 +92,9 @@ func TestPerson_Gender(t *testing.T) {
 	p := f.Person()
 	gender := p.Gender()
 
-	require.True(t, gender == "Male" || gender == "Female")
+	if !(gender == "Male" || gender == "Female") {
+		t.Fatal("gender must be male or female")
+	}
 }
 
 func TestPerson_GenderMale(t *testing.T) {
@@ -79,7 +102,9 @@ func TestPerson_GenderMale(t *testing.T) {
 	p := f.Person()
 	genderMale := p.GenderMale()
 
-	require.True(t, genderMale == "Male")
+	if genderMale != "Male" {
+		t.Fatal("genderMale must be male")
+	}
 }
 
 func TestPerson_GenderFemale(t *testing.T) {
@@ -87,5 +112,7 @@ func TestPerson_GenderFemale(t *testing.T) {
 	p := f.Person()
 	genderFemale := p.GenderFemale()
 
-	require.True(t, genderFemale == "Female")
+	if genderFemale != "Female" {
+		t.Fatal("genderFemale must be female")
+	}
 }
diff --git a/uuid.go b/uuid.go
index a81a69a..15e49f8 100644
--- a/uuid.go
+++ b/uuid.go
@@ -1,7 +1,9 @@
 package faker
 
 import (
-	"github.com/google/uuid"
+	"crypto/rand"
+	"fmt"
+	"io"
 )
 
 // UUID is struct for UUID
@@ -11,5 +13,9 @@ type UUID struct {
 
 // V4 returns UUID V4 as string
 func (u UUID) V4() string {
-	return uuid.New().String()
+	var uuid [16]byte
+	io.ReadFull(rand.Reader, uuid[:])
+	uuid[6] = (uuid[6] & 0x0f) | 0x40 // Version 4
+	uuid[8] = (uuid[8] & 0x3f) | 0x80 // Variant is 10
+	return fmt.Sprintf("%x-%x-%x-%x-%x", uuid[0:4], uuid[4:6], uuid[6:8], uuid[8:10], uuid[10:])
 }
diff --git a/uuid_test.go b/uuid_test.go
index ea57bdf..0ddc9ab 100644
--- a/uuid_test.go
+++ b/uuid_test.go
@@ -4,8 +4,6 @@ import (
 	"regexp"
 	"testing"
 
-	"github.com/stretchr/testify/require"
-
 	"github.com/neotoolkit/faker"
 )
 
@@ -13,9 +11,12 @@ func TestUUID_v4(t *testing.T) {
 	f := faker.NewFaker()
 	value := f.UUID().V4()
 	match, err := regexp.MatchString("^[a-fA-F0-9]{8}-[a-fA-F0-9]{4}-[a-fA-F0-9]{4}-[a-fA-F0-9]{4}-[a-fA-F0-9]{12}$", value)
-
-	require.NoError(t, err)
-	require.True(t, match)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !match {
+		t.Fatal("want true, got false")
+	}
 }
 
 func TestUUID_V4UniqueInSequence(t *testing.T) {
@@ -23,5 +24,7 @@ func TestUUID_V4UniqueInSequence(t *testing.T) {
 	last := f.UUID().V4()
 	current := f.UUID().V4()
 
-	require.Equal(t, true, last != current)
+	if last == current {
+		t.Fatal("want unique uuid")
+	}
 }