diff --git a/chat.go b/chat.go
index fcaf79cf7..6181526f7 100644
--- a/chat.go
+++ b/chat.go
@@ -187,7 +187,8 @@ type ToolCall struct {
 type FunctionCall struct {
 	Name string `json:"name,omitempty"`
 	// call function with arguments in JSON format
-	Arguments string `json:"arguments,omitempty"`
+	Arguments string  `json:"arguments,omitempty"`
+	Output    *string `json:"output,omitempty"`
 }
 
 type ChatCompletionResponseFormatType string