diff --git a/docs/pyerrors/obs.html b/docs/pyerrors/obs.html
index 6fbbc868..402457c3 100644
--- a/docs/pyerrors/obs.html
+++ b/docs/pyerrors/obs.html
@@ -1757,7 +1757,7 @@
             <span class="k">if</span> <span class="n">r_name</span> <span class="ow">not</span> <span class="ow">in</span> <span class="n">obs2</span><span class="o">.</span><span class="n">e_content</span><span class="p">[</span><span class="n">e_name</span><span class="p">]:</span>
                 <span class="k">continue</span>
             <span class="n">gamma_div</span> <span class="o">+=</span> <span class="n">calc_gamma</span><span class="p">(</span><span class="n">np</span><span class="o">.</span><span class="n">ones</span><span class="p">(</span><span class="n">obs1</span><span class="o">.</span><span class="n">shape</span><span class="p">[</span><span class="n">r_name</span><span class="p">]),</span> <span class="n">np</span><span class="o">.</span><span class="n">ones</span><span class="p">(</span><span class="n">obs2</span><span class="o">.</span><span class="n">shape</span><span class="p">[</span><span class="n">r_name</span><span class="p">]),</span> <span class="n">obs1</span><span class="o">.</span><span class="n">idl</span><span class="p">[</span><span class="n">r_name</span><span class="p">],</span> <span class="n">obs2</span><span class="o">.</span><span class="n">idl</span><span class="p">[</span><span class="n">r_name</span><span class="p">],</span> <span class="n">idl_d</span><span class="p">[</span><span class="n">r_name</span><span class="p">])</span>
-            <span class="n">e_N</span> <span class="o">+=</span> <span class="n">np</span><span class="o">.</span><span class="n">sum</span><span class="p">(</span><span class="n">np</span><span class="o">.</span><span class="n">ones_like</span><span class="p">(</span><span class="n">idl_d</span><span class="p">[</span><span class="n">r_name</span><span class="p">]))</span>
+            <span class="n">e_N</span> <span class="o">+=</span> <span class="nb">len</span><span class="p">(</span><span class="n">idl_d</span><span class="p">[</span><span class="n">r_name</span><span class="p">])</span>
         <span class="n">gamma</span> <span class="o">/=</span> <span class="n">gamma_div</span>
 
         <span class="c1"># Bias correction hep-lat/0306017 eq. (49)</span>