--- /etc/defaults/periodic.conf.orig	2014-11-11 21:03:42.000000000 +0000
+++ /etc/defaults/periodic.conf	2015-11-06 12:15:55.134177165 +0000
@@ -314,8 +314,8 @@
 		    "use \$$var instead." >&2
 		case "$value" in
 		[Yy][Ee][Ss])
-			$var=YES
-			$periodvar=daily
+			eval $var=YES
+			eval $periodvar=daily
 			;;
 		*)
 			eval $var=\"$value\"