diff --git a/docs/INTEGRATION_GUIDE.md b/docs/INTEGRATION_GUIDE.md
index 6103c24..a0b42ee 100644
--- a/docs/INTEGRATION_GUIDE.md
+++ b/docs/INTEGRATION_GUIDE.md
@@ -135,6 +135,7 @@ try {
 ```
 
 `UserInfoException` with `invalid_token` can occur when provider-side subject scope is no longer active (for example user/project disabled) between token issuance and userinfo retrieval.
+`TokenExchangeException` with `invalid_grant` can also occur when provider-side client/user/project state is inactive at exchange time.
 
 ## Operational guidance