diff --git a/lib/Hoymiles/src/commands/ActivePowerControlCommand.h b/lib/Hoymiles/src/commands/ActivePowerControlCommand.h
index 35398816..ebcf71b4 100644
--- a/lib/Hoymiles/src/commands/ActivePowerControlCommand.h
+++ b/lib/Hoymiles/src/commands/ActivePowerControlCommand.h
@@ -11,7 +11,7 @@ typedef enum { // ToDo: to be verified by field tests
 
 class ActivePowerControlCommand : public DevControlCommand {
 public:
-    ActivePowerControlCommand(uint64_t target_address = 0, uint64_t router_address = 0);
+    explicit ActivePowerControlCommand(uint64_t target_address = 0, uint64_t router_address = 0);
     virtual bool handleResponse(InverterAbstract* inverter, fragment_t fragment[], uint8_t max_fragment_id);
     virtual void gotTimeout(InverterAbstract* inverter);