diff --git a/inc/button_handler.hpp b/inc/button_handler.hpp
index b3c65f5..baa7400 100644
--- a/inc/button_handler.hpp
+++ b/inc/button_handler.hpp
@@ -39,7 +39,7 @@
      *
      * @param[in] bus - sdbusplus connection object
      */
-    Handler(sdbusplus::bus::bus& bus);
+    explicit Handler(sdbusplus::bus::bus& bus);
 
   private:
     /**