diff --git a/CHANGELOG.txt b/CHANGELOG.txt
index 5fdb8aa48..e3262279e 100644
--- a/CHANGELOG.txt
+++ b/CHANGELOG.txt
@@ -7,6 +7,7 @@ Changelog
  * Fix: Paste / drag operations done entirely with the mouse are now correctly picked up as edits within the rich text editor (Matt Fozard)
  * Fix: Logic for cancelling the "unsaved changes" check on form submission has been fixed to work cross-browser (Stephen Rice)
  * Fix: The up / down / delete controls on the "Promoted search results" form no longer trigger a form submission (Matt Westcott)
+ * Fix: Opening preview window no longer performs user-agent sniffing, and now works correctly on IE11 (Matt Westcott)
 
 
 1.4.4 (10.05.2016)
diff --git a/docs/releases/1.4.5.rst b/docs/releases/1.4.5.rst
index 05a46ab00..6f78a714d 100644
--- a/docs/releases/1.4.5.rst
+++ b/docs/releases/1.4.5.rst
@@ -16,3 +16,4 @@ Bug fixes
  * Paste / drag operations done entirely with the mouse are now correctly picked up as edits within the rich text editor (Matt Fozard)
  * Logic for cancelling the "unsaved changes" check on form submission has been fixed to work cross-browser (Stephen Rice)
  * The up / down / delete controls on the "Promoted search results" form no longer trigger a form submission (Matt Westcott)
+ * Opening preview window no longer performs user-agent sniffing, and now works correctly on IE11 (Matt Westcott)