diff --git a/requests_oauthlib/oauth2_session.py b/requests_oauthlib/oauth2_session.py
index 5a062977..75b62ef6 100644
--- a/requests_oauthlib/oauth2_session.py
+++ b/requests_oauthlib/oauth2_session.py
@@ -246,6 +246,7 @@ def refresh_token(self, token_url, refresh_token=None, body='', auth=None,
         log.debug('Prepared refresh token request body %s', body)
         r = self.post(token_url, data=dict(urldecode(body)), auth=auth,
                       timeout=timeout, verify=verify)
+        r.raise_for_status()
         log.debug('Request to refresh token completed with status %s.',
                   r.status_code)
         log.debug('Response headers were %s and content %s.',