diff --git a/Blimp/Blimp.cpp b/Blimp/Blimp.cpp
index 9c9f457b13..c923e0ea61 100644
--- a/Blimp/Blimp.cpp
+++ b/Blimp/Blimp.cpp
@@ -72,7 +72,9 @@ const AP_Scheduler::Task Blimp::scheduler_tasks[] = {
     SCHED_TASK(arm_motors_check,      10,     50,  18),
     SCHED_TASK(update_altitude,       10,    100,  21),
     SCHED_TASK(three_hz_loop,          3,     75,  24),
+#if AP_SERVORELAYEVENTS_ENABLED
     SCHED_TASK_CLASS(AP_ServoRelayEvents,  &blimp.ServoRelayEvents,      update_events, 50,     75,  27),
+#endif
     SCHED_TASK_CLASS(AP_Baro,              &blimp.barometer,             accumulate,    50,     90,  30),
 #if LOGGING_ENABLED == ENABLED
     SCHED_TASK(full_rate_logging,     50,    50,  33),
diff --git a/Blimp/system.cpp b/Blimp/system.cpp
index cec5103bb5..828d19b139 100644
--- a/Blimp/system.cpp
+++ b/Blimp/system.cpp
@@ -58,7 +58,9 @@ void Blimp::init_ardupilot()
     // motors initialised so parameters can be sent
     ap.initialised_params = true;
 
+#if AP_RELAY_ENABLED
     relay.init();
+#endif
 
     /*
      *  setup the 'main loop is dead' check. Note that this relies on