diff --git a/web/styles/left_sidebar.css b/web/styles/left_sidebar.css
index 0529d10901..eb6a819b6a 100644
--- a/web/styles/left_sidebar.css
+++ b/web/styles/left_sidebar.css
@@ -530,10 +530,6 @@ li.active-sub-filter {
             /* Unset inherited :focus outline. */
             outline: 0;
         }
-
-        .filter-icon i.fa-clock-o {
-            font-size: 15px;
-        }
     }
 
     .active-filter {
diff --git a/web/templates/left_sidebar.hbs b/web/templates/left_sidebar.hbs
index e68e057d5a..98474fef3d 100644
--- a/web/templates/left_sidebar.hbs
+++ b/web/templates/left_sidebar.hbs
@@ -16,21 +16,21 @@
                 <li class="top_left_recent_view left-sidebar-navigation-condensed-item">
                     <a href="#recent" class="tippy-left-sidebar-tooltip left-sidebar-navigation-icon-container" data-tooltip-template-id="recent-conversations-tooltip-template">
                         <span class="filter-icon">
-                            <i class="fa fa-clock-o" aria-hidden="true"></i>
+                            <i class="zulip-icon zulip-icon-clock" aria-hidden="true"></i>
                         </span>
                     </a>
                 </li>
                 <li class="top_left_all_messages left-sidebar-navigation-condensed-item">
                     <a href="#all_messages" class="home-link tippy-left-sidebar-tooltip left-sidebar-navigation-icon-container" data-tooltip-template-id="all-message-tooltip-template">
                         <span class="filter-icon">
-                            <i class="fa fa-align-left" aria-hidden="true"></i>
+                            <i class="zulip-icon zulip-icon-all-messages" aria-hidden="true"></i>
                         </span>
                     </a>
                 </li>
                 <li class="top_left_mentions left-sidebar-navigation-condensed-item">
                     <a href="#narrow/is/mentioned" class="tippy-left-sidebar-tooltip left-sidebar-navigation-icon-container" data-tooltip-template-id="mentions-tooltip-template">
                         <span class="filter-icon">
-                            <i class="fa fa-at" aria-hidden="true"></i>
+                            <i class="zulip-icon zulip-icon-at-sign" aria-hidden="true"></i>
                         </span>
                         <span class="unread_count"></span>
                     </a>