diff --git a/install.sh b/install.sh
index 3f96c4f..da46245 100755
--- a/install.sh
+++ b/install.sh
@@ -58,7 +58,8 @@ function sudo_root {
 set -Eeuo pipefail
 assert_supported_distro
 sudo_root
-deployment_type_adjective="${1:-installed}"
+
+deployment_type_adjective="${1:-installed}" # self-upgrade provides 'upgrade'
 
 if once_installed; then upgrade; else install; fi