diff --git a/uuid.go b/uuid.go
index 1f1f2b7..4712ac2 100644
--- a/uuid.go
+++ b/uuid.go
@@ -17,5 +17,5 @@ func (UUID) V4() (uuid string) {
 	io.ReadFull(rand.Reader, uiq[:])
 	uiq[6] = (uiq[6] & 0x0f) | 0x40           // Version 4
 	uiq[8] = (uiq[8]&(0xff>>2) | (0x02 << 6)) // Variant RFC4122
-	return fmt.Sprintf("%x%x%x%x%x", uiq[0:4], uiq[4:6], uiq[6:8], uiq[8:10], uiq[10:])
+	return fmt.Sprintf("%x-%x-%x-%x-%x", uiq[0:4], uiq[4:6], uiq[6:8], uiq[8:10], uiq[10:])
 }
diff --git a/uuid_test.go b/uuid_test.go
index 73b7b49..215552f 100644
--- a/uuid_test.go
+++ b/uuid_test.go
@@ -8,7 +8,7 @@ import (
 func TestUUIDv4(t *testing.T) {
 	f := New()
 	value := f.UUID().V4()
-	match, err := regexp.MatchString("^[a-fA-F0-9]{8}[a-fA-F0-9]{4}4[a-fA-F0-9]{3}[8|9|aA|bB][a-fA-F0-9]{3}[a-fA-F0-9]{12}$", value)
+	match, err := regexp.MatchString("^[a-fA-F0-9]{8}-[a-fA-F0-9]{4}-4[a-fA-F0-9]{3}-[8|9|aA|bB][a-fA-F0-9]{3}-[a-fA-F0-9]{12}$", value)
 	Expect(t, true, err == nil)
 	Expect(t, true, match)
 }