diff --git a/ArduCopter/AP_Arming.cpp b/ArduCopter/AP_Arming.cpp
index 30226a9020..4167e6a753 100644
--- a/ArduCopter/AP_Arming.cpp
+++ b/ArduCopter/AP_Arming.cpp
@@ -233,12 +233,12 @@ bool AP_Arming_Copter::parameter_checks(bool display_failure)
 
         // Inverted flight feature disabled for Heli Single and Dual frames
         if (copter.g2.frame_class.get() != AP_Motors::MOTOR_FRAME_HELI_QUAD &&
-            rc().find_channel_for_option(RC_Channel::aux_func_t::INVERTED) != nullptr) {
+            rc().find_channel_for_option(RC_Channel::AUX_FUNC::INVERTED) != nullptr) {
             check_failed(ARMING_CHECK_PARAMETERS, display_failure, "Inverted flight option not supported");
             return false;
         }
         // Ensure an Aux Channel is configured for motor interlock
-        if (rc().find_channel_for_option(RC_Channel::aux_func_t::MOTOR_INTERLOCK) == nullptr) {
+        if (rc().find_channel_for_option(RC_Channel::AUX_FUNC::MOTOR_INTERLOCK) == nullptr) {
             check_failed(ARMING_CHECK_PARAMETERS, display_failure, "Motor Interlock not configured");
             return false;
         }
diff --git a/ArduCopter/RC_Channel.cpp b/ArduCopter/RC_Channel.cpp
index b613cb141a..dde5eb48e3 100644
--- a/ArduCopter/RC_Channel.cpp
+++ b/ArduCopter/RC_Channel.cpp
@@ -69,7 +69,7 @@ RC_Channel * RC_Channels_Copter::get_arming_channel(void) const
 }
 
 // init_aux_switch_function - initialize aux functions
-void RC_Channel_Copter::init_aux_function(const aux_func_t ch_option, const AuxSwitchPos ch_flag)
+void RC_Channel_Copter::init_aux_function(const AUX_FUNC ch_option, const AuxSwitchPos ch_flag)
 {
     // init channel options
     switch(ch_option) {
@@ -156,7 +156,7 @@ void RC_Channel_Copter::do_aux_function_change_mode(const Mode::Number mode,
 }
 
 // do_aux_function - implement the function invoked by auxiliary switches
-bool RC_Channel_Copter::do_aux_function(const aux_func_t ch_option, const AuxSwitchPos ch_flag)
+bool RC_Channel_Copter::do_aux_function(const AUX_FUNC ch_option, const AuxSwitchPos ch_flag)
 {
     switch(ch_option) {
         case AUX_FUNC::FLIP:
diff --git a/ArduCopter/RC_Channel.h b/ArduCopter/RC_Channel.h
index 6d9d9f9426..b0ba3ebb14 100644
--- a/ArduCopter/RC_Channel.h
+++ b/ArduCopter/RC_Channel.h
@@ -11,8 +11,8 @@ public:
 
 protected:
 
-    void init_aux_function(aux_func_t ch_option, AuxSwitchPos) override;
-    bool do_aux_function(aux_func_t ch_option, AuxSwitchPos) override;
+    void init_aux_function(AUX_FUNC ch_option, AuxSwitchPos) override;
+    bool do_aux_function(AUX_FUNC ch_option, AuxSwitchPos) override;
 
 private:
 
diff --git a/ArduCopter/tuning.cpp b/ArduCopter/tuning.cpp
index babc53b9ff..c2cea3c72f 100644
--- a/ArduCopter/tuning.cpp
+++ b/ArduCopter/tuning.cpp
@@ -22,7 +22,7 @@ void Copter::tuning()
     }
 
     // exit immediately if a function is assigned to channel 6
-    if ((RC_Channel::aux_func_t)rc6->option.get() != RC_Channel::AUX_FUNC::DO_NOTHING) {
+    if ((RC_Channel::AUX_FUNC)rc6->option.get() != RC_Channel::AUX_FUNC::DO_NOTHING) {
         return;
     }