diff --git a/README.md b/README.md
index 2774571..6d28e24 100644
--- a/README.md
+++ b/README.md
@@ -109,6 +109,19 @@ Example package:
 * [pkg/de-p1st-networkmanager/systemd.preset](pkg/de-p1st-networkmanager/systemd.preset)
 * [pkg/de-p1st-networkmanager/PKGBUILD](pkg/de-p1st-networkmanager/PKGBUILD)
 
+**Note**:
+
+Running `systemctl preset-all` resets all installed unit files to the defaults configured in the preset policy files.
+
+This implies: **All manual changes** such as `systemctl enable serviceXYZ` will get lost!
+
+To avoid this, enable your services with systemd-presets!
+
+```shell
+echo 'enable NetworkManager.service' | sudo tee -a /usr/lib/systemd/system-preset/20-custom.preset
+sudo systemctl preset-all
+```
+
 ### Multiple providers
 
 Example: