diff --git a/README.md b/README.md
index 65aeae05568c3a89b9ea97553b1db494bd01aa4c..904a47d94b2366d3dbc145e9f15930497af94d70 100644
--- a/README.md
+++ b/README.md
@@ -551,6 +551,10 @@ ros2 run lrs_exec tst_command --ros-args -r __ns:=/ex0 -p command:=test-turtle-2
 
 --->
 
+### 2.4
+
+For how to test the ardupilot things with a copter see: https://gitlab.liu.se/lrs2/lrs_ardupilot/-/blob/main/README.md
+
 ## Additional Information
 
 Many additional properties of TST are described here: