diff --git a/redislock.go b/redislock.go
index b1b00b5..68fdfff 100644
--- a/redislock.go
+++ b/redislock.go
@@ -49,9 +49,13 @@ func New(client RedisClient) *Client {
 	return &Client{client: client}
 }
 
+type RedisLocker interface {
+	Obtain(ctx context.Context, key string, ttl time.Duration, opt *Options) (RedisLock, error)
+}
+
 // Obtain tries to obtain a new lock using a key with the given TTL.
 // May return ErrNotObtained if not successful.
-func (c *Client) Obtain(ctx context.Context, key string, ttl time.Duration, opt *Options) (*Lock, error) {
+func (c *Client) Obtain(ctx context.Context, key string, ttl time.Duration, opt *Options) (RedisLock, error) {
 	// Create a random token
 	token, err := c.randomToken()
 	if err != nil {
@@ -113,6 +117,15 @@ func (c *Client) randomToken() (string, error) {
 
 // --------------------------------------------------------------------
 
+type RedisLock interface {
+	Key() string
+	Token() string
+	Metadata() string
+	TTL(ctx context.Context) (time.Duration, error)
+	Refresh(ctx context.Context, ttl time.Duration, opt *Options) error
+	Release(ctx context.Context) error
+}
+
 // Lock represents an obtained, distributed lock.
 type Lock struct {
 	client *Client
@@ -121,7 +134,7 @@ type Lock struct {
 }
 
 // Obtain is a short-cut for New(...).Obtain(...).
-func Obtain(ctx context.Context, client RedisClient, key string, ttl time.Duration, opt *Options) (*Lock, error) {
+func Obtain(ctx context.Context, client RedisClient, key string, ttl time.Duration, opt *Options) (RedisLock, error) {
 	return New(client).Obtain(ctx, key, ttl, opt)
 }