diff --git a/_includes/header.html b/_includes/header.html
index ba5b65e6e2..33ae409009 100644
--- a/_includes/header.html
+++ b/_includes/header.html
@@ -54,8 +54,8 @@
             <li class="dropdown-header">Previous Releases</li>
             <li><a href="/documentation/5.1/">5.1.0</a></li>
             <li><a href="/documentation/5.0/">5.0.1</a></li>
-	    <li><a href="/documentation/4.0/">4.0.5</a></li>
-	    <li><a href="/documentation/3.5/">3.5.2</a></li>
+            <li><a href="/documentation/4.0/">4.0.5</a></li>
+            <li><a href="/documentation/3.5/">3.5.2</a></li>
             <li><a href="/documentation/3.4/">3.4.1</a></li>
             <li><a href="/documentation/3.3/">3.3.0</a></li>
             <li><a href="/documentation/3.2/">3.2.2</a></li>