diff --git a/docs/en/mavlink/adding_messages.md b/docs/en/mavlink/adding_messages.md
index a0226dd26d..74a97e8664 100644
--- a/docs/en/mavlink/adding_messages.md
+++ b/docs/en/mavlink/adding_messages.md
@@ -80,16 +80,16 @@ So if you have created a custom message in PX4 you won't be able to use it unles
 
 ### Updating QGroundControl
 
-You will need to [Build QGroundControl](https://docs.qgroundcontrol.com/master/en/qgc-dev-guide/getting_started/index.html) including a pre-built C library that contains your custom messages.
+You will need to [Build QGroundControl](https://docs.qgroundcontrol.com/master/en/qgc-dev-guide/getting_started/index.html) with your custom messages included.
 
-QGC uses a pre-built C library that must be located at [/qgroundcontrol/libs/mavlink/include/mavlink](https://github.com/mavlink/qgroundcontrol/tree/master/libs/mavlink/include/mavlink) in the QGC source.
+QGC fetches MAVLink via CMake using settings defined in [`cmake/CustomOptions.cmake`](https://github.com/mavlink/qgroundcontrol/blob/master/cmake/CustomOptions.cmake).
+The key variables are `QGC_MAVLINK_GIT_REPO` (the MAVLink repository to fetch), `QGC_MAVLINK_GIT_TAG` (a specific commit or tag), and `QGC_MAVLINK_DIALECT` (the dialect, default: `all`).
+To use a custom MAVLink repository or dialect, override these in a `CustomOverrides.cmake` file in the QGC source root.
 
-By default this is pre-included as a submodule from <https://github.com/mavlink/c_library_v2> but you can [generate your own MAVLink Libraries](https://mavlink.io/en/getting_started/generate_libraries.html).
+QGC uses the **all** dialect by default, which includes **common.xml**.
+You can include your messages in either file, or [generate your own MAVLink Libraries](https://mavlink.io/en/getting_started/generate_libraries.html).
 
-QGC uses the **all.xml** dialect by default, which includes **common.xml**.
-You can include your messages in either file.
-
-Note that if you use your own _custom dialect_ then it should include **ArduPilotMega.xml** (or it will miss all the existing messages), and you will need to change the dialect used by setting it in [`MAVLINK_CONF`](https://github.com/mavlink/qgroundcontrol/blob/master/QGCExternalLibs.pri#L52) when running _qmake_.
+Note that if you use your own _custom dialect_ then it should include **all.xml** (or it may miss all the existing messages), and you will need to set `QGC_MAVLINK_DIALECT` accordingly in `CustomOverrides.cmake`.
 
 ### Updating MAVSDK