diff --git a/bridge/core/auth/credential.go b/bridge/core/auth/credential.go
index 7aad755296e7831cdd453189794f5d02c2696c7a..9504fd706dfc0ab0813016aca14b720391ccaec1 100644
--- a/bridge/core/auth/credential.go
+++ b/bridge/core/auth/credential.go
@@ -22,8 +22,8 @@ const (
 type CredentialKind string
 
 const (
-	KindToken         = "token"
-	KindLoginPassword = "login-password"
+	KindToken         CredentialKind = "token"
+	KindLoginPassword CredentialKind = "login-password"
 )
 
 var ErrCredentialNotExist = errors.New("credential doesn't exist")