diff --git a/roles/calibre/tasks/main.yml b/roles/calibre/tasks/main.yml
index 722012e7c..e84467bb6 100644
--- a/roles/calibre/tasks/main.yml
+++ b/roles/calibre/tasks/main.yml
@@ -5,7 +5,11 @@
     path: "/usr/bin/calibre"
   register: calib_executable
 
-# The 8 lines below appear unecessary as of 2018-06-26 -- as tested on RPi.
+# The 8 lines below were breaking IIAB installs on Ubuntu 16.04 as of early
+# July 2018 (https://github.com/iiab/iiab/issues/883) and were tested as
+# unecessary on Raspbian Lite on RPi 3 B+ (calibre_via-debs: True) and
+# Ubuntu 18.04 (calibre_via_python: True).  PR #856 is the fix for now.
+
 #- name: Install Calibre via OS's package installer (IF /usr/bin/calibre MISSING)
 #  package:
 #    name: "{{ item }}"