diff --git a/client/transport/oauth.go b/client/transport/oauth.go
index aebbd316e..5406b4d41 100644
--- a/client/transport/oauth.go
+++ b/client/transport/oauth.go
@@ -105,6 +105,7 @@ type AuthServerMetadata struct {
 	ResponseTypesSupported            []string `json:"response_types_supported"`
 	GrantTypesSupported               []string `json:"grant_types_supported,omitempty"`
 	TokenEndpointAuthMethodsSupported []string `json:"token_endpoint_auth_methods_supported,omitempty"`
+	CodeChallengeMethodsSupported     []string `json:"code_challenge_methods_supported,omitempty"`
 }
 
 // OAuthHandler handles OAuth authentication for HTTP requests