diff --git a/GScan200.cpp b/GScan200.cpp
index 7aca0d5..e52e875 100644
--- a/GScan200.cpp
+++ b/GScan200.cpp
@@ -5,7 +5,7 @@
 #include "opencv2/opencv.hpp"
 #include "twain.h"
 #include "device_common.h"
-#include "GDevice.h";
+#include "GDevice.h"
 
 GScan200::GScan200()
 {
@@ -116,9 +116,11 @@ bool GScan200::Get_IsImageQueueEmpty()
 
 void GScan200::reset()
 {
-	m_dev->stop();
-	this_thread::sleep_for(chrono::milliseconds(200));
-	m_pImages.clear();
+	if (m_dev) {
+		m_dev->stop();
+		this_thread::sleep_for(chrono::milliseconds(200));
+		m_pImages.clear();
+	}
 }
 
 void GScan200::setdecodepixtype(int twpixtype)