--- a/toolkit/content/license.html
+++ b/toolkit/content/license.html
@@ -117,16 +117,17 @@
       <li><a href="about:license#jszip">JSZip License</a></li>
       <li><a href="about:license#jemalloc">jemalloc License</a></li>
       <li><a href="about:license#jquery">jQuery License</a></li>
       <li><a href="about:license#k_exp">k_exp License</a></li>
       <li><a href="about:license#kernel32-sys">kernel32-sys License</a></li>
       <li><a href="about:license#khronos">Khronos group License</a></li>
       <li><a href="about:license#kiss_fft">Kiss FFT License</a></li>
       <li><a href="about:license#ktmw32-sys">ktmw32-sys License</a></li>
+      <li><a href="about:license#languages-tags">languages-tags License</a></li>
       <li><a href="about:license#lcms">lcms License</a></li>
 #ifdef MOZ_USE_LIBCXX
       <li><a href="about:license#libc++">libc++ License</a></li>
 #endif
       <li><a href="about:license#libcubeb">libcubeb License</a></li>
       <li><a href="about:license#libevent">libevent License</a></li>
       <li><a href="about:license#libffi">libffi License</a></li>
       <li><a href="about:license#libjingle">libjingle License</a></li>
@@ -4422,16 +4423,46 @@ AUTHORS OR COPYRIGHT HOLDERS BE LIABLE F
 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 THE SOFTWARE.
 </pre>
 
 
     <hr>
 
+    <h1><a id="language-tags"></a>language-tags License</h1>
+
+    <p>This license applies to files in the directory
+    <code>third_party/rust/language-tags</code>.</p>
+
+<pre>
+Copyright (c) 2015 Pyfisch
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
+</pre>
+
+
+    <hr>
+
     <h1><a id="lcms"></a>lcms License</h1>
 
     <p>This license applies to files in the directory
       <span class="path">modules/pdfium/pdfium/third_party/lcms2-2.6/</span>.</p>
 
 <pre>
 Copyright (c) 1998-2014 Marti Maria Saguer