diff --git a/SerialController.cpp b/SerialController.cpp
index 10c634a..f48cf70 100644
--- a/SerialController.cpp
+++ b/SerialController.cpp
@@ -226,7 +226,6 @@ m_speed(speed),
 m_assertRTS(assertRTS),
 m_fd(-1)
 {
-	assert(!device.empty());
 }
 
 CSerialController::~CSerialController()
@@ -235,6 +234,7 @@ CSerialController::~CSerialController()
 
 bool CSerialController::open()
 {
+	assert(!m_device.empty());
 	assert(m_fd == -1);
 
 #if defined(__APPLE__)