diff --git a/how-to-self-host-hardened-strongswan-ikev2-ipsec-vpn-server-for-ios-and-macos/README.md b/how-to-self-host-hardened-strongswan-ikev2-ipsec-vpn-server-for-ios-and-macos/README.md
index b40657b..de72117 100644
--- a/how-to-self-host-hardened-strongswan-ikev2-ipsec-vpn-server-for-ios-and-macos/README.md
+++ b/how-to-self-host-hardened-strongswan-ikev2-ipsec-vpn-server-for-ios-and-macos/README.md
@@ -231,7 +231,7 @@ $ source ~/.bashrc
 #### Install cURL and Python
 
 ```shell
-apt install -y curl python
+apt install -y curl python3
 ```
 
 #### Generate random IPv6 ULA and save to environment variables
@@ -241,8 +241,8 @@ Shout out to [Andrew Ho](https://gist.github.com/andrewlkho/31341da4f5953b8d977a
 The following command downloads and runs [ulagen.py](./ulagen.py) ([PGP signature](./ulagen.py.sig), [PGP public key](https://sunknudsen.com/sunknudsen.asc)).
 
 ```console
-$ curl -s https://sunknudsen.com/static/media/privacy-guides/how-to-self-host-hardened-strongswan-ikev2-ipsec-vpn-server-for-ios-and-macos/ulagen.py | python | grep "First subnet" | awk '{print "STRONGSWAN_IPV6_ULA="$3}' | tee -a ~/.bashrc
-STRONGSWAN_IPV6_ULA=fdcb:f7a1:38ec::/64
+$ curl -s https://sunknudsen.com/static/media/privacy-guides/how-to-self-host-hardened-strongswan-ikev2-ipsec-vpn-server-for-ios-and-macos/ulagen.py | python3 | grep "First subnet" | awk '{print "STRONGSWAN_IPV6_ULA="$3}' | tee -a ~/.bashrc
+STRONGSWAN_IPV6_ULA=fdba:8ce0:c301::/64
 
 $ source ~/.bashrc
 ```
diff --git a/how-to-self-host-hardened-strongswan-ikev2-ipsec-vpn-server-for-ios-and-macos/ulagen.py b/how-to-self-host-hardened-strongswan-ikev2-ipsec-vpn-server-for-ios-and-macos/ulagen.py
index 166c578..7cd5be1 100755
--- a/how-to-self-host-hardened-strongswan-ikev2-ipsec-vpn-server-for-ios-and-macos/ulagen.py
+++ b/how-to-self-host-hardened-strongswan-ikev2-ipsec-vpn-server-for-ios-and-macos/ulagen.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 import hashlib
 import time
@@ -16,13 +16,13 @@ def time_ntpformat():
     
 def main():
   h = hashlib.sha1()
-  h.update(get_eui64() + str(time_ntpformat()))
+  h.update(str(get_eui64() + str(time_ntpformat())).encode("utf-8"))
   globalid = h.hexdigest()[0:10]
 
   prefix = ":".join(("fd" + globalid[0:2], globalid[2:6], globalid[6:10]))
-  print "Prefix:       " + prefix + "::/48"
-  print "First subnet: " + prefix + "::/64"
-  print "Last subnet:  " + prefix + ":ffff::/64"
+  print("Prefix:       " + prefix + "::/48")
+  print("First subnet: " + prefix + "::/64")
+  print("Last subnet:  " + prefix + ":ffff::/64")
 
 if __name__ == "__main__":
   main()
diff --git a/how-to-self-host-hardened-strongswan-ikev2-ipsec-vpn-server-for-ios-and-macos/ulagen.py.sig b/how-to-self-host-hardened-strongswan-ikev2-ipsec-vpn-server-for-ios-and-macos/ulagen.py.sig
index 023cfca..fa4bdca 100644
Binary files a/how-to-self-host-hardened-strongswan-ikev2-ipsec-vpn-server-for-ios-and-macos/ulagen.py.sig and b/how-to-self-host-hardened-strongswan-ikev2-ipsec-vpn-server-for-ios-and-macos/ulagen.py.sig differ