diff --git a/hgdriver/hgdev/hg_scanner_300.cpp b/hgdriver/hgdev/hg_scanner_300.cpp
index 01caea1..1b1958b 100644
--- a/hgdriver/hgdev/hg_scanner_300.cpp
+++ b/hgdriver/hgdev/hg_scanner_300.cpp
@@ -1019,6 +1019,8 @@ int hg_scanner_300::set_sleep_time(int data)
 {
 	std::lock_guard<std::mutex>      lock(io_lock_);
 	int ret = SCANNER_ERR_OK;
+	if (data == -1)
+		data = 0x7FFFFFFF;
 	USBCB usbcb = { setting3288dsp::SET_SLEEP_TIME,data, 0};
 	ret = writeusb(usbcb);
 	return ret;