diff --git a/libraries/RC_Channel/RC_Channel.h b/libraries/RC_Channel/RC_Channel.h
index 377bb957af..c80f42335d 100644
--- a/libraries/RC_Channel/RC_Channel.h
+++ b/libraries/RC_Channel/RC_Channel.h
@@ -513,7 +513,7 @@ public:
 
     // check if flight mode channel is assigned RC option
     // return true if assigned
-    bool flight_mode_channel_conflicts_with_rc_option();
+    bool flight_mode_channel_conflicts_with_rc_option() const;
 
     // flight_mode_channel_number must be overridden in vehicle specific code
     virtual int8_t flight_mode_channel_number() const = 0;
@@ -549,7 +549,7 @@ private:
     AP_Int32  _options;
     AP_Int32  _protocols;
 
-    RC_Channel *flight_mode_channel();
+    RC_Channel *flight_mode_channel() const;
 
     // Allow override by default at start
     bool _gcs_overrides_enabled = true;
diff --git a/libraries/RC_Channel/RC_Channels.cpp b/libraries/RC_Channel/RC_Channels.cpp
index 2ac94a390f..4284451833 100644
--- a/libraries/RC_Channel/RC_Channels.cpp
+++ b/libraries/RC_Channel/RC_Channels.cpp
@@ -183,7 +183,7 @@ void RC_Channels::init_aux_all()
 //
 // Support for mode switches
 //
-RC_Channel *RC_Channels::flight_mode_channel()
+RC_Channel *RC_Channels::flight_mode_channel() const
 {
     const int8_t num = flight_mode_channel_number();
     if (num <= 0) {
@@ -192,7 +192,7 @@ RC_Channel *RC_Channels::flight_mode_channel()
     if (num >= NUM_RC_CHANNELS) {
         return nullptr;
     }
-    return channel(num-1);
+    return rc_channel(num-1);
 }
 
 void RC_Channels::reset_mode_switch()
@@ -219,7 +219,7 @@ void RC_Channels::read_mode_switch()
 
 // check if flight mode channel is assigned RC option
 // return true if assigned
-bool RC_Channels::flight_mode_channel_conflicts_with_rc_option()
+bool RC_Channels::flight_mode_channel_conflicts_with_rc_option() const
 {
     RC_Channel *chan = flight_mode_channel();
     if (chan == nullptr) {