diff --git a/src/oidc.rs b/src/oidc.rs
index c99e29d..f70bf28 100644
--- a/src/oidc.rs
+++ b/src/oidc.rs
@@ -52,7 +52,7 @@ impl DeviceAuthorizationResponse {
 #[derive(Clone, Debug, Serialize, Deserialize)]
 pub struct TokenResponse {
     pub access_token: String,
-    pub refresh_token: String,
+    pub refresh_token: Option<String>,
     pub scope: Option<String>,
     pub token_type: String,
     pub id_token: Option<String>,