diff --git a/frontend_tests/node_tests/echo.js b/frontend_tests/node_tests/echo.js
index ba18d0b2f2..3657199d47 100644
--- a/frontend_tests/node_tests/echo.js
+++ b/frontend_tests/node_tests/echo.js
@@ -249,6 +249,7 @@ var bugdown_data = JSON.parse(fs.readFileSync(path.join(__dirname, '../../zerver
 (function test_message_flags() {
   var input = "/me is testing this";
   var message = {subject: "No links here", raw_content: input};
+  message.flags = ['read'];
   echo.apply_markdown(message);
   echo._add_message_flags(message);
 
@@ -256,26 +257,25 @@ var bugdown_data = JSON.parse(fs.readFileSync(path.join(__dirname, '../../zerver
   assert(message.flags.indexOf('read') !== -1);
   assert(message.flags.indexOf('is_me_message') !== -1);
 
-  input = "testing this @**all**";
+  input = "testing this @**all** @**Cordelia Lear**";
   message = {subject: "No links here", raw_content: input};
   echo.apply_markdown(message);
   echo._add_message_flags(message);
 
-  assert.equal(message.flags.length, 2);
-  assert(message.flags.indexOf('read') !== -1);
+  assert.equal(message.flags.length, 1);
   assert(message.flags.indexOf('mentioned') !== -1);
 
   input = "test @all";
   message = {subject: "No links here", raw_content: input};
   echo.apply_markdown(message);
   echo._add_message_flags(message);
-  assert.equal(message.flags.length, 2);
+  assert.equal(message.flags.length, 1);
   assert(message.flags.indexOf('mentioned') !== -1);
 
   input = "test @any";
   message = {subject: "No links here", raw_content: input};
   echo.apply_markdown(message);
   echo._add_message_flags(message);
-  assert.equal(message.flags.length, 1);
+  assert.equal(message.flags.length, 0);
   assert(message.flags.indexOf('mentioned') === -1);
 }());
diff --git a/static/js/echo.js b/static/js/echo.js
index ea014d2637..bcf711ec96 100644
--- a/static/js/echo.js
+++ b/static/js/echo.js
@@ -30,16 +30,28 @@ exports.contains_bugdown = function contains_bugdown(content) {
     return markedup !== undefined;
 };
 
+function push_uniquely(lst, elem) {
+    if (!_.contains(lst, elem)) {
+        lst.push(elem);
+    }
+}
+
 exports.apply_markdown = function apply_markdown(message) {
+    if (message.flags === undefined) {
+        message.flags = [];
+    }
+
     // Our python-markdown processor appends two \n\n to input
     var options = {
         userMentionHandler: function (name) {
             var person = people.get_by_name(name);
             if (person !== undefined) {
+                push_uniquely(message.flags, 'mentioned');
                 return '<span class="user-mention" data-user-email="' + person.email + '">' +
                        '@' + person.full_name +
                        '</span>';
             } else if (name === 'all' || name === 'everyone') {
+                push_uniquely(message.flags, 'mentioned');
                 return '<span class="user-mention" data-user-email="*">' +
                        '@' + name +
                        '</span>';
@@ -81,25 +93,13 @@ function truncate_precision(float) {
 }
 
 function add_message_flags(message) {
-    // Locally delivered messages cannot be unread (since we sent them), nor
-    // can they alert the user
-    var flags = ["read"];
-
-    // Messages that mention the sender should highlight as well
-    var self_mention = 'data-user-email="' + page_params.email + '"';
-    var wildcard_mention = 'data-user-email="*"';
-    if (message.content.indexOf(self_mention) > -1 ||
-        message.content.indexOf(wildcard_mention) > -1) {
-        flags.push("mentioned");
-    }
+    // Note: mention flags are set in apply_markdown()
 
     if (message.raw_content.indexOf('/me ') === 0 &&
         message.content.indexOf('<p>') === 0 &&
         message.content.lastIndexOf('</p>') === message.content.length - 4) {
-        flags.push('is_me_message');
+        message.flags.push('is_me_message');
     }
-
-    message.flags = flags;
 }
 
 function add_subject_links(message) {
@@ -145,6 +145,11 @@ function insert_local_message(message_request, local_id) {
     // for zulip.js:add_message
     // Keep this in sync with changes to compose.create_message_object
     var message = $.extend({}, message_request);
+
+    // Locally delivered messages cannot be unread (since we sent them), nor
+    // can they alert the user.
+    message.flags = ['read']; // we may add more flags later
+
     message.raw_content = message.content;
     // NOTE: This will parse synchronously. We're not using the async pipeline
     exports.apply_markdown(message);