diff --git a/scripts/calibre-install-latest-rpi.sh b/scripts/calibre-install-latest-rpi.sh
index 941f29306..56a35a70a 100755
--- a/scripts/calibre-install-latest-rpi.sh
+++ b/scripts/calibre-install-latest-rpi.sh
@@ -1,12 +1,16 @@
 #!/bin/bash
 
-# Thanks to Jerry Vonau (https://github.com/jvonau) who made
-# this critical breakthrough (Calibre 3.x on Raspbian) possible!
-# The latest available is 3.21 available from testing
-# https://packages.debian.org/search?keywords=calibre
-# (SEE http://raspbian.raspberrypi.org/raspbian/pool/main/c/calibre/ 
-#  OR http://archive.raspbian.org/raspbian/pool/main/c/calibre/ ?)
-# Might break future updates, you have been warned.
+# Thanks to Jerry Vonau (https://github.com/jvonau) who made this critical
+# breakthrough possible!
+#
+# Calibre 3.23 is the latest available from testing as of 2018-05-10:
+#
+#   http://raspbian.raspberrypi.org/raspbian/pool/main/c/calibre/
+#   http://archive.raspbian.org/raspbian/pool/main/c/calibre/
+#   https://packages.debian.org/search?keywords=calibre
+#   http://deb.debian.org/debian/pool/main/c/calibre/
+#
+# Might break future updates; you have been warned.
 
 export DEBIAN_FRONTEND=noninteractive
 # Updates calibre calibre-bin to version 3.21 or ... from testing