diff --git a/libexec/rc/network.subr b/libexec/rc/network.subr
index 2d9ee8913c7..76a5b94bc40 100644
--- a/libexec/rc/network.subr
+++ b/libexec/rc/network.subr
@@ -1047,7 +1047,7 @@ ifalias_af_common_handler()
 		esac
 	done
 	# Process the last component if any.
-	if [ -n "$_tmpargs}" ]; then
+	if [ -n "${_tmpargs}" ]; then
 		case $_tmpargs in
 		${_af}[[:space:]]*[0-9a-fA-F]-*)
 			ifalias_af_common_handler $_if $_af $_action \