diff --git a/auth/auth_test.go b/auth/auth_test.go
index 55e7c1c..169ebaa 100644
--- a/auth/auth_test.go
+++ b/auth/auth_test.go
@@ -13,10 +13,10 @@ import (
 )
 
 const (
-	peeper = "polp"
-	key    = "plop"
-	cookie = "auth"
-	cost   = 10
+	peeper     = "polp"
+	key        = "plop"
+	cookieName = "auth"
+	cost       = 10
 
 	username = "plop"
 	password = "ploppwd"
@@ -55,7 +55,7 @@ func getBackend() *Backend {
 }
 
 func login(w http.ResponseWriter, r *http.Request) {
-	a := New(getBackend(), peeper, cookie, key, cost)
+	a := New(getBackend(), peeper, cookieName, key, cost)
 	err := a.Login(w, r, username, password)
 	if err != nil {
 		fmt.Fprintf(w, "%s", err)
@@ -66,7 +66,7 @@ func login(w http.ResponseWriter, r *http.Request) {
 
 }
 func logout(w http.ResponseWriter, r *http.Request) {
-	a := New(getBackend(), peeper, cookie, key, cost)
+	a := New(getBackend(), peeper, cookieName, key, cost)
 	err := a.Logout(w, r)
 	if err != nil {
 		fmt.Fprintf(w, "%s", err)
@@ -76,7 +76,7 @@ func logout(w http.ResponseWriter, r *http.Request) {
 	w.WriteHeader(http.StatusOK)
 }
 func check(w http.ResponseWriter, r *http.Request) {
-	a := New(getBackend(), peeper, cookie, key, cost)
+	a := New(getBackend(), peeper, cookieName, key, cost)
 	u, err := a.CurrentUser(w, r)
 	if err != nil {
 		w.WriteHeader(http.StatusInternalServerError)
diff --git a/users/users.go b/users/users.go
index eba6842..ec9fdf7 100644
--- a/users/users.go
+++ b/users/users.go
@@ -20,6 +20,9 @@ const (
 	deleteTokenQuery = `DELETE FROM tokens WHERE user_id=$1 AND value=$2;`
 )
 
+// ErrUnknownUser returned web a user does'nt exist
+var ErrUnknownUser = fmt.Errorf("users: user does'nt exist")
+
 // User represents an user
 type User struct {
 	sqly.BaseModel
@@ -38,6 +41,9 @@ func Get(q sqlx.Queryer, name string) (*User, error) {
 	u := &User{}
 	err := q.QueryRowx(getUserQuery, name).StructScan(u)
 	if err != nil {
+		if err.Error() == "sql: no rows in result set" {
+			return nil, ErrUnknownUser
+		}
 		return nil, err
 	}
 	return u, nil
@@ -125,3 +131,8 @@ func (u *User) DeleteToken(ex *sqlx.DB, value string) error {
 	}
 	return nil
 }
+
+// GetHash implements auth.User interface
+func (u *User) GetHash() string {
+	return u.Hash
+}
diff --git a/users/users_test.go b/users/users_test.go
index 1416348..0076bc6 100644
--- a/users/users_test.go
+++ b/users/users_test.go
@@ -86,7 +86,7 @@ func TestUser(t *testing.T) {
 		if err == nil {
 			t.Fatal("We expect an error here, the user didn't exist anymore")
 		}
-		if err.Error() != "sql: no rows in result set" {
+		if err != ErrUnknownUser {
 			t.Fatalf("Unexpected error: %q", err)
 		}
 		if u != nil {