diff --git a/dto/openai_request.go b/dto/openai_request.go
index a6fc3f66..76a86662 100644
--- a/dto/openai_request.go
+++ b/dto/openai_request.go
@@ -393,7 +393,7 @@ func (m *MediaContent) GetVideoUrl() *MessageVideoUrl {
 
 type MessageImageUrl struct {
 	Url      string `json:"url"`
-	Detail   string `json:"detail"`
+	Detail   string `json:"detail,omitempty"`
 	MimeType string
 }