diff --git a/data/copyright.html b/data/copyright.html
index 8ecb61f7cd..dc11dffb58 100644
--- a/data/copyright.html
+++ b/data/copyright.html
@@ -130,7 +130,8 @@
 
     <li><a href="http://www.daemonology.net/bsdiff/">bsdiff</a>; <a href="#bsd3-license" class="license">BSD License</a></li>
 
-    <li><a href="https://github.com/progschj/ThreadPool">ThreadPool</a></li>
+    <li><a href="https://github.com/progschj/ThreadPool">ThreadPool</a><br>
+      &copy; 2012 Jakob Progsch, Václav Zeman; <a href="#zlib-license" class="license">zlib License</a></li>
 
     <li><a href="http://uscilab.github.io/cereal/">Cereal</a><br>
       &copy; 2014 Randolph Voorhies, Shane Grant; <a href="#bsd3-license" class="license">BSD License</a></li>
@@ -1417,5 +1418,25 @@ of the copyright holder.</p>
   <p>Further context, best practice and guidance can be found in the <a href="http://www.nationalarchives.gov.uk/information-management/re-using-public-sector-information/uk-government-licensing-framework/">UK Government Licensing Framework section</a> on The National Archives website.</p>
 
 </div>
+
+<div class="section">
+  <h2 id="zlib-license">zlib License</h2>
+
+  <p>This software is provided 'as-is', without any express or implied
+  warranty.  In no event will the authors be held liable for any damages
+  arising from the use of this software.</p>
+
+  <p>Permission is granted to anyone to use this software for any purpose,
+  including commercial applications, and to alter it and redistribute it
+  freely, subject to the following restrictions:</p>
+
+  <p>1. The origin of this software must not be misrepresented; you must not
+     claim that you wrote the original software. If you use this software
+     in a product, an acknowledgment in the product documentation would be
+     appreciated but is not required.</p>
+  <p>2. Altered source versions must be plainly marked as such, and must not be
+     misrepresented as being the original software.</p>
+  <p>3. This notice may not be removed or altered from any source distribution.</p>
+</div>
 </body>
 </html>