diff --git a/initrd/install.h b/initrd/install.h
index c864d55..4d4aaf4 100644
--- a/initrd/install.h
+++ b/initrd/install.h
@@ -32,7 +32,7 @@
 
 	if [ -e /etc/nsswitch.conf ]; then
 		INST_CFG /etc/nsswitch.conf
-		databases="$(awk '/^(group|hosts)/ {for(i = 2; i <= NF; ++i) print $i}' /etc/nsswitch.conf | LC_ALL=C sort -u)"
+		databases="$(awk '/^(group|hosts)/ {for(i = 2; i <= NF; ++i) if($i !~ /[^a-z0-9_-]/) db[$i]=0}  END {for(d in db) print d}' /etc/nsswitch.conf)"
 		for db in $databases; do
 			for f in /lib/*/"libnss_$db"*; do
 				INST_LIB "$f"