diff --git a/pkg/providers/openai_compat/provider.go b/pkg/providers/openai_compat/provider.go
index 9b404dd77..73fac3435 100644
--- a/pkg/providers/openai_compat/provider.go
+++ b/pkg/providers/openai_compat/provider.go
@@ -71,7 +71,7 @@ func (p *Provider) Chat(ctx context.Context, messages []Message, tools []ToolDef
 
 	if maxTokens, ok := asInt(options["max_tokens"]); ok {
 		lowerModel := strings.ToLower(model)
-		if strings.Contains(lowerModel, "glm") || strings.Contains(lowerModel, "o1") {
+		if strings.Contains(lowerModel, "glm") || strings.Contains(lowerModel, "o1") || strings.Contains(lowerModel, "gpt-5") {
 			requestBody["max_completion_tokens"] = maxTokens
 		} else {
 			requestBody["max_tokens"] = maxTokens