diff --git a/usr.sbin/pc-sysinstall/backend-query/sys-mem.sh b/usr.sbin/pc-sysinstall/backend-query/sys-mem.sh
index d8555af9b6a4..bc0e3a2fc813 100755
--- a/usr.sbin/pc-sysinstall/backend-query/sys-mem.sh
+++ b/usr.sbin/pc-sysinstall/backend-query/sys-mem.sh
@@ -25,7 +25,4 @@
 #
 # $FreeBSD$
 
-MEM=`sysctl hw.realmem | sed "s|hw.realmem: ||g"`
-MEM=`expr $MEM / 1024`
-MEM=`expr $MEM / 1024`
-echo $MEM
+expr $(sysctl -n hw.realmem) / 1048576