diff --git a/scripts/generate-dev-bundle.sh b/scripts/generate-dev-bundle.sh
index 8796f68834..56e3eaf3f9 100755
--- a/scripts/generate-dev-bundle.sh
+++ b/scripts/generate-dev-bundle.sh
@@ -124,7 +124,13 @@ npm install https://github.com/ariya/esprima/tarball/5044b87f94fb802d9609f1426c8
 npm install https://github.com/meteor/node-source-map-support/tarball/980e444c8346bbe29992fd3086bab0456b8d8667
 
 # uglify-js has a bug which drops 'undefined' in arrays:
-# https://github.com/mishoo/UglifyJS2/pull/97
+# This has finally been merged:
+#   https://github.com/mishoo/UglifyJS2/commit/b1febde3
+# so we should consider upgrading to a newer version of Uglify soon.
+# This version was forked from 3a591c4 which was v2.2.5. A casual glance
+# at the commits between there and b1febde3 suggests that we should
+# be able to upgrade without any negative consequences (no obvious
+# API changes, etc).
 npm install https://github.com/meteor/UglifyJS2/tarball/aa5abd14d3
 
 # If you update the version of fibers in the dev bundle, also update the "npm