diff --git a/include/ExternalSensor.hpp b/include/ExternalSensor.hpp
index 3ca3c8a..30147fd 100644
--- a/include/ExternalSensor.hpp
+++ b/include/ExternalSensor.hpp
@@ -56,7 +56,7 @@
 
     std::chrono::steady_clock::time_point writeLast;
     std::chrono::steady_clock::duration writeTimeout;
-    bool writeAlive;
+    bool writeAlive{false};
     bool writePerishable;
     std::function<void(const std::chrono::steady_clock::time_point& now)>
         writeHook;