diff --git a/radio/src/mixer_scheduler.cpp b/radio/src/mixer_scheduler.cpp
index b29c821c8..82dfb7086 100644
--- a/radio/src/mixer_scheduler.cpp
+++ b/radio/src/mixer_scheduler.cpp
@@ -37,13 +37,16 @@ static MixerSchedule mixerSchedules[NUM_MODULES];
 
 uint16_t getMixerSchedulerPeriod()
 {
+#if defined(INTERNAL_MODULE)
   if (mixerSchedules[INTERNAL_MODULE].period) {
     return mixerSchedules[INTERNAL_MODULE].period;
   }
-  else if (mixerSchedules[EXTERNAL_MODULE].period) {
+#endif
+#if defined(EXTERNAL_MODULE)
+  if (mixerSchedules[EXTERNAL_MODULE].period) {
     return mixerSchedules[EXTERNAL_MODULE].period;
   }
-    
+#endif
   return MIXER_SCHEDULER_DEFAULT_PERIOD_US;
 }
 
diff --git a/radio/src/tasks.cpp b/radio/src/tasks.cpp
index 8346b2ceb..f85c6a6b2 100644
--- a/radio/src/tasks.cpp
+++ b/radio/src/tasks.cpp
@@ -174,7 +174,14 @@ TASK_FUNCTION(mixerTask)
       doMixerCalculations();
 
       // TODO: fix runMask
-      sendSynchronousPulses((1 << INTERNAL_MODULE) | (1 << EXTERNAL_MODULE));
+      uint8_t runMask = 0;
+#if defined(INTERNAL_MODULE)
+      runMask != (1 << INTERNAL_MODULE)
+#endif
+#if defined(EXTERNAL_MODULE)
+      runMask != (1 << EXTERNAL_MODULE)
+#endif
+      sendSynchronousPulses(runMask);
 
       doMixerPeriodicUpdates();