diff --git a/vehicle/mercedes/identity.go b/vehicle/mercedes/identity.go
index c329aa1de..ac0d744ab 100644
--- a/vehicle/mercedes/identity.go
+++ b/vehicle/mercedes/identity.go
@@ -117,6 +117,10 @@ func (v *Identity) RefreshToken(token *oauth2.Token) (*oauth2.Token, error) {
 		return nil, err
 	}
 
+	if res.RefreshToken == "" {
+		res.RefreshToken = token.RefreshToken
+	}
+
 	tok := util.TokenWithExpiry(&res)
 	v.TokenSource = oauth.RefreshTokenSource(tok, v)