diff --git a/static/js/composebox_typeahead.js b/static/js/composebox_typeahead.js
index 361428df86..a224b3ed08 100644
--- a/static/js/composebox_typeahead.js
+++ b/static/js/composebox_typeahead.js
@@ -287,13 +287,13 @@ exports.compose_content_begins_typeahead = function (query) {
             return false;
         }
 
-        current_token = q.substring(q.lastIndexOf('@') + 1);
+        current_token = current_token.substring(1);
         if (current_token.length < 1 || current_token.lastIndexOf('*') !== -1) {
             return false;
         }
 
         this.completing = 'mention';
-        this.token = current_token.substring(current_token.indexOf("@") + 1);
+        this.token = current_token;
         var all_item = {
             special_item_text: "all (Notify everyone)",
             email: "all",
@@ -317,18 +317,19 @@ exports.compose_content_begins_typeahead = function (query) {
             return false;
         }
 
-        current_token = q.substring(q.lastIndexOf('#') + 1);
-        if (current_token.length < 1) {
+        if (current_token.length === 1) {
             return false;
         }
 
+        current_token = current_token.substring(1);
+
         // Don't autocomplete if there is a space following a '#'
         if (current_token[0] === " ") {
             return false;
         }
 
         this.completing = 'stream';
-        this.token = current_token.substring(current_token.indexOf("#")+1);
+        this.token = current_token;
         return stream_data.subscribed_subs();
     }
     return false;