diff --git a/client/index.html b/client/index.html
index 9f6d64d6..5502e712 100644
--- a/client/index.html
+++ b/client/index.html
@@ -49,7 +49,7 @@
 								<h1 class="title">The Lounge is loading…</h1>
 							</div>
 							<div class="col-xs-12">
-								<p id="loading-page-message">Loading the app… <a href="http://enable-javascript.com/" target="_blank">Make sure to have JavaScript enabled.</a></p>
+								<p id="loading-page-message">Loading the app… <a href="http://enable-javascript.com/" target="_blank" rel="noopener">Make sure to have JavaScript enabled.</a></p>
 								<p id="loading-slow">This is taking longer than it should, there might be connectivity issues.</p>
 								<script async src="js/loading-slow-alert.js"></script>
 							</div>
@@ -402,7 +402,7 @@
 								</p>
 								<p>
 									A color reference can be found
-									<a href="http://www.mirc.com/colors.html" target="_blank">here</a>.
+									<a href="http://modern.ircdocs.horse/formatting.html#colors" target="_blank" rel="noopener">here</a>.
 								</p>
 							</div>
 						</div>
@@ -478,7 +478,7 @@
 								</p>
 								<p>
 									A color reference can be found
-									<a href="http://www.mirc.com/colors.html" target="_blank">here</a>.
+									<a href="http://modern.ircdocs.horse/formatting.html#colors" target="_blank" rel="noopener">here</a>.
 								</p>
 							</div>
 						</div>
@@ -575,7 +575,7 @@
 								<p>
 									Send a <abbr title="Client-to-client protocol">CTCP</abbr>
 									request. Read more about this on
-									<a href="https://en.wikipedia.org/wiki/Client-to-client_protocol" target="_blank">the dedicated Wikipedia article</a>.
+									<a href="https://en.wikipedia.org/wiki/Client-to-client_protocol" target="_blank" rel="noopener">the dedicated Wikipedia article</a>.
 								</p>
 							</div>
 						</div>
@@ -809,15 +809,15 @@
 						<p class="about">
 							<% if (gitCommit) { %>
 								The Lounge is running from source
-								(<a href="https://github.com/thelounge/lounge/tree/<%= gitCommit %>" target="_blank"><code><%= gitCommit %></code></a>).<br>
+								(<a href="https://github.com/thelounge/lounge/tree/<%= gitCommit %>" target="_blank" rel="noopener"><code><%= gitCommit %></code></a>).<br>
 							<% } else { %>
 								The Lounge is in version <strong><%= version %></strong>
-								(<a href="https://github.com/thelounge/lounge/releases/tag/v<%= version %>" target="_blank">See release notes</a>).<br>
+								(<a href="https://github.com/thelounge/lounge/releases/tag/v<%= version %>" target="_blank" rel="noopener">See release notes</a>).<br>
 							<% } %>
 
-							<a href="https://thelounge.github.io/" target="_blank">Website</a><br>
-							<a href="https://thelounge.github.io/docs/" target="_blank">Documentation</a><br>
-							<a href="https://github.com/thelounge/lounge/issues/new" target="_blank">Report a bug</a>
+							<a href="https://thelounge.github.io/" target="_blank" rel="noopener">Website</a><br>
+							<a href="https://thelounge.github.io/docs/" target="_blank" rel="noopener">Documentation</a><br>
+							<a href="https://github.com/thelounge/lounge/issues/new" target="_blank" rel="noopener">Report a bug</a>
 						</p>
 					</div>
 				</div>