diff --git a/IPython/nbconvert/templates/fullhtml.tpl b/IPython/nbconvert/templates/fullhtml.tpl
index 11e8acc..343c17c 100644
--- a/IPython/nbconvert/templates/fullhtml.tpl
+++ b/IPython/nbconvert/templates/fullhtml.tpl
@@ -28,6 +28,9 @@ pre {
 }
 </style>
 
+<!-- Custom stylesheet, it must be in the same directory as the html file -->
+<link rel="stylesheet" href="custom.css">
+
 <script src="https://c328740.ssl.cf1.rackcdn.com/mathjax/latest/MathJax.js?config=TeX-AMS_HTML" type="text/javascript">
 
 </script>
diff --git a/IPython/nbconvert/templates/reveal.tpl b/IPython/nbconvert/templates/reveal.tpl
index ab035cc..1a402f6 100644
--- a/IPython/nbconvert/templates/reveal.tpl
+++ b/IPython/nbconvert/templates/reveal.tpl
@@ -85,6 +85,10 @@ div.output_prompt {
 text-align: inherit;
 }
 </style>
+
+<!-- Custom stylesheet, it must be in the same directory as the html file -->
+<link rel="stylesheet" href="custom.css">
+
 </head>
 {% endblock header%}