diff --git a/scripts/libmakepkg/util/pkgbuild.sh.in b/scripts/libmakepkg/util/pkgbuild.sh.in
index 2a4bd3af..08b35f53 100644
--- a/scripts/libmakepkg/util/pkgbuild.sh.in
+++ b/scripts/libmakepkg/util/pkgbuild.sh.in
@@ -18,7 +18,7 @@
 #   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #
 
-[[ -n "$LIBMAKEPKG_UTIL_PKGBUILD_SH" ]] && return
+[[ -n "${LIBMAKEPKG_UTIL_PKGBUILD_SH:-}" ]] && return
 LIBMAKEPKG_UTIL_PKGBUILD_SH=1