diff --git a/doc/compile.md b/doc/compile.md
index 55d1ded..3d348ca 100644
--- a/doc/compile.md
+++ b/doc/compile.md
@@ -36,6 +36,10 @@ Check that these packages were activated automatically:
  - Network -> tcpdump
  - Utilities -> dbus
 
+*Note: do not use `defconfig` / diffconfig / etc. because they do not work when we upgrade 
+between major versions. They tend to create frankenstein builds. So really avoid them,
+we lost enough time with this feature.
+
 ```
 make download
 make -j $(nproc)