diff --git a/install.sh b/install.sh
index 3828d94..8f56eb5 100755
--- a/install.sh
+++ b/install.sh
@@ -5,10 +5,11 @@ if [ "${EUID}" -ne 0 ]; then
   exit
 fi
 
-# check for Ubuntu 22.04 (jammy) or Debian 12 (bookworm)
-os_codename=`lsb_release -cs`
-if [ $os_codename != jammy ] && [ $os_codename != bookworm ]; then
-  echo "This installer only runs on Ubuntu 22.04 (jammy) or Debian 12 (Bookworm), bailing out."
+# check for Debian 12 (bookworm)
+os_id=`lsb_release -is`
+os_release=`lsb_release -rs`
+if [ $os_id != Debian ] || [ $os_release != 12 ]; then
+  echo "This installer only runs on Debian 12 (Bookworm), bailing out."
   exit 1
 fi
 
@@ -18,7 +19,7 @@ if [ -f "/usr/local/bin/vhost.sh" ]; then
   exit
 fi
 
-# check for existing Let's Encrypt install
+# check for existing web server software installs
 if [ -d "/etc/apache2/" ] || [ -d "/etc/php/" ] || [ -d "/etc/varnish/" ]; then
   echo
   echo "WARNING: Apache, Varnish and/or PHP are already installed."