diff --git a/static/js/narrow.js b/static/js/narrow.js
index 510128957a..694cd423ea 100644
--- a/static/js/narrow.js
+++ b/static/js/narrow.js
@@ -152,7 +152,7 @@ exports.activate = function (raw_operators, opts) {
     }
 
     if (!was_narrowed_already) {
-        unread.messages_read_in_narrow = false;
+        unread.set_messages_read_in_narrow(false);
     }
 
     // IMPORTANT!  At this point we are heavily committed to
diff --git a/static/js/unread.js b/static/js/unread.js
index 30691666c4..abcaf588cc 100644
--- a/static/js/unread.js
+++ b/static/js/unread.js
@@ -9,6 +9,9 @@ var exports = {};
 
 exports.suppress_unread_counts = true;
 exports.messages_read_in_narrow = false;
+exports.set_messages_read_in_narrow = function (value) {
+    exports.messages_read_in_narrow = value;
+};
 
 function make_id_set() {
     /* This is just a basic set class where
diff --git a/static/js/unread_ops.js b/static/js/unread_ops.js
index 18f56ab755..8402414aaa 100644
--- a/static/js/unread_ops.js
+++ b/static/js/unread_ops.js
@@ -40,7 +40,7 @@ exports.process_read_messages_event = function (message_ids) {
         if (current_msg_list === message_list.narrowed) {
             // I'm not sure this entirely makes sense for all server
             // notifications.
-            unread.messages_read_in_narrow = true;
+            unread.set_messages_read_in_narrow(true);
         }
 
         unread.mark_as_read(message_id);
@@ -70,7 +70,7 @@ exports.notify_server_messages_read = function (messages, options) {
 
     _.each(messages, function (message) {
         if (current_msg_list === message_list.narrowed) {
-            unread.messages_read_in_narrow = true;
+            unread.set_messages_read_in_narrow(true);
         }
 
         unread.mark_as_read(message.id);