diff --git a/avr/modules/ma_light/main.asm b/avr/modules/ma_light/main.asm
index 03d0c90..04e0a6f 100644
--- a/avr/modules/ma_light/main.asm
+++ b/avr/modules/ma_light/main.asm
@@ -124,10 +124,14 @@ MotionLight_OnPacketReceived:
   breq MotionLight_OnPacketReceived_report
   cpi r16, CPRO_CMD_VALUE_SET
   breq MotionLight_OnPacketReceived_set
+MotionLight_OnPacketReceived_clcRet:
   clc                                          ; unexpected msg
   ret
 MotionLight_OnPacketReceived_report:
   rcall CPRO_ReadValue                         ; (none)
+  mov r16, r18
+  or r16, r19
+  breq MotionLight_OnPacketReceived_clcRet     ; zero value, ignore
   rcall motionLightHasSource                   ; (r16, r24, Y)
   brcs MotionLight_OnPacketReceived_turnOn
   ret