diff --git a/speech.go b/speech.go
index f2442b92..b9344ac6 100644
--- a/speech.go
+++ b/speech.go
@@ -74,7 +74,7 @@ func (c *Client) CreateSpeech(ctx context.Context, request CreateSpeechRequest)
 		err = ErrInvalidVoice
 		return
 	}
-	req, err := c.newRequest(ctx, http.MethodPost, c.fullURL("/audio/speech", request.Model),
+	req, err := c.newRequest(ctx, http.MethodPost, c.fullURL("/audio/speech", string(request.Model)),
 		withBody(request),
 		withContentType("application/json; charset=utf-8"),
 	)