diff --git a/BUILD.md b/BUILD.md
index 9f49216e..8b845583 100644
--- a/BUILD.md
+++ b/BUILD.md
@@ -263,3 +263,6 @@ meson x --buildtype release --strip -Db_lto=true \
 ninja -Cx
 sudo ninja -Cx install
 ```
+
+The server only works with a matching client version (this server works with the
+`master` branch).