diff --git a/static/js/compose.js b/static/js/compose.js
index b18a6d66b1..b76b1fb721 100644
--- a/static/js/compose.js
+++ b/static/js/compose.js
@@ -138,9 +138,9 @@ exports.empty_topic_placeholder = function () {
 
 function create_message_object() {
     // Topics are optional, and we provide a placeholder if one isn't given.
-    var subject = compose_state.topic();
-    if (subject === "") {
-        subject = compose.empty_topic_placeholder();
+    var topic = compose_state.topic();
+    if (topic === "") {
+        topic = compose.empty_topic_placeholder();
     }
 
     var content = make_uploads_relative(compose_state.message_content());
@@ -152,8 +152,8 @@ function create_message_object() {
         sender_id: page_params.user_id,
         queue_id: page_params.queue_id,
         stream: '',
-        subject: '',
     };
+    util.set_topic(message, '');
 
     if (message.type === "private") {
         // TODO: this should be collapsed with the code in composebox_typeahead.js
@@ -171,7 +171,7 @@ function create_message_object() {
         if (sub) {
             message.stream_id = sub.stream_id;
         }
-        message.subject = subject;
+        util.set_topic(message, topic);
     }
     return message;
 }
diff --git a/static/js/util.js b/static/js/util.js
index 101264fb02..c89e62aa77 100644
--- a/static/js/util.js
+++ b/static/js/util.js
@@ -291,6 +291,10 @@ exports.get_match_topic = function (obj) {
     return obj.match_subject;
 };
 
+exports.set_topic = function (obj, topic) {
+    obj.subject = topic;
+};
+
 return exports;
 
 }());