diff --git a/backend/open_webui/utils/oauth.py b/backend/open_webui/utils/oauth.py
index 0c7ddc489a..76f1ebb346 100644
--- a/backend/open_webui/utils/oauth.py
+++ b/backend/open_webui/utils/oauth.py
@@ -1008,6 +1008,12 @@ class OAuthClientManager:
                 ) as resp:
                     if resp.status < 400:
                         return True
+
+                    # Bot challenge pages echo the request URL, so their keywords say nothing about the client
+                    if resp.headers.get('cf-mitigated'):
+                        log.debug('Skipping OAuth preflight for client %s: bot challenge', client_info.client_id)
+                        return True
+
                     response_text = await resp.text()
 
                     error = None