diff --git a/installers/full_install_osm.sh b/installers/full_install_osm.sh
index b22b9e2..ffd4a27 100755
--- a/installers/full_install_osm.sh
+++ b/installers/full_install_osm.sh
@@ -650,6 +650,7 @@
 }
 
 function install_lightweight() {
+    [ "$USER" == "root" ] && FATAL "You are running the installer as root. The installer is prepared to be executed as a normal user with sudo privileges."
     echo "Installing lightweight build of OSM"
     LWTEMPDIR="$(mktemp -d -q --tmpdir "installosmlight.XXXXXX")"
     trap 'rm -rf "${LWTEMPDIR}"' EXIT