diff --git a/sdk_container/src/third_party/portage-stable/eclass/app-alternatives.eclass b/sdk_container/src/third_party/portage-stable/eclass/app-alternatives.eclass
index c6924bfc6d..32afedba1e 100644
--- a/sdk_container/src/third_party/portage-stable/eclass/app-alternatives.eclass
+++ b/sdk_container/src/third_party/portage-stable/eclass/app-alternatives.eclass
@@ -1,4 +1,4 @@
-# Copyright 2022 Gentoo Authors
+# Copyright 2022-2024 Gentoo Authors
 # Distributed under the terms of the GNU General Public License v2
 
 # @ECLASS: app-alternatives.eclass
@@ -21,7 +21,7 @@ case ${EAPI} in
 	*) die "${ECLASS}: EAPI ${EAPI:-0} unsupported."
 esac
 
-if [[ ! ${_APP_ALTERNATIVES_ECLASS} ]]; then
+if [[ -z ${_APP_ALTERNATIVES_ECLASS} ]]; then
 _APP_ALTERNATIVES_ECLASS=1
 
 # @ECLASS_VARIABLE: ALTERNATIVES
@@ -36,7 +36,7 @@ _APP_ALTERNATIVES_ECLASS=1
 # @DESCRIPTION:
 # Set ebuild metadata variables.
 _app-alternatives_set_globals() {
-	debug-print-function ${FUNCNAME} "${@}"
+	debug-print-function ${FUNCNAME} "$@"
 
 	if [[ ${ALTERNATIVES@a} != *a* ]]; then
 		die 'ALTERNATIVES must be an array.'
@@ -71,7 +71,7 @@ _app-alternatives_set_globals
 # @DESCRIPTION:
 # Get the flag name for the selected alternative (i.e. the USE flag set).
 get_alternative() {
-	debug-print-function ${FUNCNAME} "${@}"
+	debug-print-function ${FUNCNAME} "$@"
 
 	local flag
 	for flag in "${ALTERNATIVES[@]%%:*}"; do