diff --git a/en/recovery-challenge.cgi b/en/recovery-challenge.cgi
index 041dde1..3292aac 100755
--- a/en/recovery-challenge.cgi
+++ b/en/recovery-challenge.cgi
@@ -106,7 +106,7 @@ case "$arg_method" in
 		;;
 esac
 
-sedcmd=" -e 's/USERNAME/$arg_username/' -e 's/CHALLENGE/$(<$runtime_dir/$arg_username)/' -e 's/KEYID/$keyid/' -e 's/NAV/$(php $(dirname $0)/nav.php)/' -e 's/FOOTER/$($(dirname $0)/footer.cgi)/'"
+sedcmd=" -e 's/USERNAME/$arg_username/' -e 's/CHALLENGE/$(<$runtime_dir/$arg_username)/' -e 's/KEYID/$keyid/' -e 's\NAV\$(php $(dirname $0)\nav.php)\' -e 's\FOOTER\$($(dirname $0)\footer.cgi)\'"
 sedcmd="$sedcmd $(if [[ $nokey == 1 ]]; then
 	printf '%s' '-e "s/NOKEY/This user has no <code>.pgp.asc</code> file/"'
 else