diff --git a/src/slic3r/GUI/Mouse3DController.hpp b/src/slic3r/GUI/Mouse3DController.hpp
index 5d6b5ba8c..e686e12cc 100644
--- a/src/slic3r/GUI/Mouse3DController.hpp
+++ b/src/slic3r/GUI/Mouse3DController.hpp
@@ -139,7 +139,7 @@ class Mouse3DController
     std::map<std::string, Params> m_params_by_device;
 
     mutable State 		m_state;
-    std::atomic<bool> 	m_connected;
+    std::atomic<bool> 	m_connected { false };
     std::string 		m_device_str;
 
 #if ! __APPLE__