diff --git a/services/web/app/coffee/Features/Labels/LabelsHandler.coffee b/services/web/app/coffee/Features/Labels/LabelsHandler.coffee
index bc2d9a9c32..f6739e3b3a 100644
--- a/services/web/app/coffee/Features/Labels/LabelsHandler.coffee
+++ b/services/web/app/coffee/Features/Labels/LabelsHandler.coffee
@@ -17,6 +17,9 @@ module.exports = LabelsHandler =
 				callback(null, projectLabels)
 
 	getLabelsForDoc: (projectId, docId, callback=(err, docLabels)->) ->
+		# Flush doc first, because this action is often performed while
+		# a document is being edited by the client. By contrast,
+		# `getAllLabelsForProject` is called only when a project/editor is loaded
 		DocumentUpdaterHandler.flushDocToMongo projectId, docId, (err) ->
 			if err?
 				return callback(err)