diff --git a/debian/postinst b/debian/postinst
index 056903220b94e7e1aea4d0fe3249422c19668325..ec06e6d086602e421c4f3ed26dbf93996ed05fc5 100644
--- a/debian/postinst
+++ b/debian/postinst
@@ -159,7 +159,7 @@ if [ -f /etc/openvpn/$ORGNICK-server.conf ]; then
 else
 	OCTET2=$(($RANDOM % 16 + 16))
 	OCTET3=$(($RANDOM % 256))
-	SERVERLINE="server 172.$OCTET2.$OCTET3.0 255.255.255.0"
+	SERVERLINE="server 172.$OCTET2.$OCTET3.0 255.255.252.0"
 fi
 
 cat <<EOF >$TMPCONF/$ORGNICK-server.conf