diff --git a/libusb.odin b/libusb.odin
index 10afa32..cae68b6 100644
--- a/libusb.odin
+++ b/libusb.odin
@@ -1088,7 +1088,7 @@ Callback_Handle :: distinct c.int
 foreign lib {
 	//----- Library initialization/deinitialization ----------------------------------
 	set_log_cb :: proc(ctx: Context, cb: Log_Cb, mode: Log_Cb_Mode) ---
-	set_option :: proc(ctx: Context, option: Option) -> Error ---
+	set_option :: proc(ctx: Context, option: Option, args: c.va_list) -> Error ---
 	init :: proc(ctx: ^Context) -> Error ---
 	init_context :: proc(ctx: ^Context, options: [^]Init_Option, num_options: c.int) -> Error ---
 	exit :: proc(ctx: Context) ---