diff --git a/libraries/AP_DDS/AP_DDS_ExternalControl.cpp b/libraries/AP_DDS/AP_DDS_ExternalControl.cpp
index 4d824f1c09418..1ded6a5ff57ab 100644
--- a/libraries/AP_DDS/AP_DDS_ExternalControl.cpp
+++ b/libraries/AP_DDS/AP_DDS_ExternalControl.cpp
@@ -58,6 +58,8 @@ bool AP_DDS_External_Control::handle_velocity_control(geometry_msgs_msg_TwistSta
         return false;
     }
 
+    // TODO handle stale data from timestamp gracefully.
+
     if (strcmp(cmd_vel.header.frame_id, BASE_LINK_FRAME_ID) == 0) {
         // Convert commands from body frame (x-forward, y-left, z-up) to NED.
         Vector3f linear_velocity;
@@ -66,14 +68,15 @@ bool AP_DDS_External_Control::handle_velocity_control(geometry_msgs_msg_TwistSta
             float(cmd_vel.twist.linear.y),
             float(-cmd_vel.twist.linear.z) };
         const float yaw_rate = -cmd_vel.twist.angular.z;
-        if (linear_velocity_base_link == Vector3f(NAN, NAN, NAN)) {
+
+        if (linear_velocity_base_link.is_all_nan()) {
             return external_control->set_yaw_rate(yaw_rate);
         }
 
         auto &ahrs = AP::ahrs();
         linear_velocity = ahrs.body_to_earth(linear_velocity_base_link);
 
-        return external_control->set_linear_velocity_and_yaw_rate(linear_velocity, yaw_rate);       
+        return external_control->set_linear_velocity_and_yaw_rate(linear_velocity, yaw_rate);
     }
 
     else if (strcmp(cmd_vel.header.frame_id, MAP_FRAME) == 0) {