diff --git a/usr.sbin/bsdconfig/share/sysrc.subr b/usr.sbin/bsdconfig/share/sysrc.subr
index 80deaa8be6c..51aabcccad5 100644
--- a/usr.sbin/bsdconfig/share/sysrc.subr
+++ b/usr.sbin/bsdconfig/share/sysrc.subr
@@ -132,7 +132,7 @@ f_sysrc_get()
 		# Clear the environment of all variables, preventing the
 		# expansion of normals such as `PS1', `TERM', etc.
 		#
-		f_clean_env --except RC_CONFS RC_DEFAULTS SUCCESS
+		f_clean_env --except RC_CONFS RC_DEFAULTS
 
 		. "$RC_DEFAULTS" > /dev/null 2>&1
 
@@ -153,15 +153,11 @@ f_sysrc_get()
 		# If RC_CONFS is defined, set $rc_conf_files to an explicit
 		# value, modifying the default behavior of source_rc_confs().
 		#
-		( : ${RC_CONFS?} ) > /dev/null 2>&1
-		if [ $? -eq ${SUCCESS:-0} ]; then
+		if [ "${RC_CONFS+set}" ]; then
 			rc_conf_files="$RC_CONFS"
 			_rc_confs_set=1
 		fi
 
-		unset SUCCESS
-			# no longer needed
-
 		source_rc_confs > /dev/null 2>&1
 
 		#
diff --git a/usr.sbin/bsdconfig/startup/rcadd b/usr.sbin/bsdconfig/startup/rcadd
index d9d6a045353..8f28840bf45 100755
--- a/usr.sbin/bsdconfig/startup/rcadd
+++ b/usr.sbin/bsdconfig/startup/rcadd
@@ -46,7 +46,7 @@ ipgm=$( f_index_menu_selection $BSDCFG_LIBE/$APP_DIR/INDEX "$pgm" )
 # Options
 #
 # Inherit SHOW_DESC value if set, otherwise default to 1
-( : ${SHOW_DESC?} ) > /dev/null 2>&1 || SHOW_DESC=1
+[ "${SHOW_DESC+set}" ] || SHOW_DESC=1
 
 ############################################################ FUNCTIONS
 
diff --git a/usr.sbin/bsdconfig/startup/rcconf b/usr.sbin/bsdconfig/startup/rcconf
index 3f7c25049ea..4fb58593ebf 100755
--- a/usr.sbin/bsdconfig/startup/rcconf
+++ b/usr.sbin/bsdconfig/startup/rcconf
@@ -54,7 +54,7 @@ RCCONF_MENU_LIST=
 # Options
 #
 # Inherit SHOW_DESC value if set, otherwise default to 1
-( : ${SHOW_DESC?} ) > /dev/null 2>&1 || SHOW_DESC=1
+[ "${SHOW_DESC+set}" ] || SHOW_DESC=1
 # Selectively inherit SHOW_* value (in order of preference)
 if [ "$SHOW_DEFAULT_VALUE" ]; then
 	SHOW_DEFAULT_VALUE=1
diff --git a/usr.sbin/bsdconfig/startup/rcdelete b/usr.sbin/bsdconfig/startup/rcdelete
index a97025838c0..b431d884b2e 100755
--- a/usr.sbin/bsdconfig/startup/rcdelete
+++ b/usr.sbin/bsdconfig/startup/rcdelete
@@ -54,7 +54,7 @@ RCCONF_MENU_LIST=
 # Options
 #
 # Inherit SHOW_DESC value if set, otherwise default to 1
-( : ${SHOW_DESC?} ) > /dev/null 2>&1 || SHOW_DESC=1
+[ "${SHOW_DESC+set}" ] || SHOW_DESC=1
 # Selectively inherit SHOW_* value (in order of preference)
 if [ "$SHOW_DEFAULT_VALUE" ]; then
 	SHOW_DEFAULT_VALUE=1
@@ -348,7 +348,7 @@ while :; do
 		var="${mtag# }"
 
 		# Toggle the state-variable and loop back to menu
-		if ( eval : \${_${var}_delete?} ) > /dev/null 2>&1; then
+		if eval [ \"\${_${var}_delete+set}\" ]; then
 			unset _${var}_delete
 		else
 			setvar _${var}_delete 1
diff --git a/usr.sbin/bsdconfig/startup/rcvar b/usr.sbin/bsdconfig/startup/rcvar
index 799dd3426b1..b7a52295ea1 100755
--- a/usr.sbin/bsdconfig/startup/rcvar
+++ b/usr.sbin/bsdconfig/startup/rcvar
@@ -54,7 +54,7 @@ RCVAR_MENU_LIST=
 # Options
 #
 # Inherit SHOW_DESC value if set, otherwise default to 1
-( ${SHOW_DESC?} ) > /dev/null 2>&1 || SHOW_DESC=1
+[ "${SHOW_DESC+set}" ] || SHOW_DESC=1
 
 ############################################################ FUNCTIONS