diff --git a/sw/airborne/fms/fms_autopilot_msg.h b/sw/airborne/fms/fms_autopilot_msg.h
index 4274de33d2..dfee8f93de 100644
--- a/sw/airborne/fms/fms_autopilot_msg.h
+++ b/sw/airborne/fms/fms_autopilot_msg.h
@@ -94,7 +94,7 @@ struct __attribute__ ((packed)) AutopilotMessagePTUp
 
 struct __attribute__ ((packed)) AutopilotMessagePTDown
 {
-  uint16_t pwm_outputs_usecs[LISA_PWM_NB];
+  uint16_t pwm_outputs_usecs[LISA_PWM_OUTPUT_NB];
 };
 
 union AutopilotMessagePT