diff --git a/libraries/AP_WindVane/AP_WindVane.cpp b/libraries/AP_WindVane/AP_WindVane.cpp
index 54eceab80a..e7c3d716ef 100644
--- a/libraries/AP_WindVane/AP_WindVane.cpp
+++ b/libraries/AP_WindVane/AP_WindVane.cpp
@@ -318,7 +318,7 @@ bool AP_WindVane::start_speed_calibration()
 }
 
 // send mavlink wind message
-void AP_WindVane::send_wind(mavlink_channel_t chan)
+void AP_WindVane::send_wind(mavlink_channel_t chan) const
 {
     // exit immediately if not enabled
     if (!enabled()) {
diff --git a/libraries/AP_WindVane/AP_WindVane.h b/libraries/AP_WindVane/AP_WindVane.h
index 2067c38fbc..be0094aa69 100644
--- a/libraries/AP_WindVane/AP_WindVane.h
+++ b/libraries/AP_WindVane/AP_WindVane.h
@@ -89,7 +89,7 @@ public:
     bool start_speed_calibration();
 
     // send mavlink wind message
-    void send_wind(mavlink_channel_t chan);
+    void send_wind(mavlink_channel_t chan) const;
 
     // parameter block
     static const struct AP_Param::GroupInfo var_info[];