diff -r 910e293663cb Doc/tools/pydoctheme/static/pydoctheme.css
--- a/Doc/tools/pydoctheme/static/pydoctheme.css	Fri Sep 09 00:05:42 2016 -0700
+++ b/Doc/tools/pydoctheme/static/pydoctheme.css	Fri Sep 09 14:11:24 2016 +0200
@@ -27,6 +27,7 @@
     border-radius: 5px;
     line-height: 130%;
     font-size: smaller;
+    position: relative;
 }
 
 div.sphinxsidebar h3, div.sphinxsidebar h4 {
@@ -41,6 +42,22 @@
     margin-bottom: 0.4em;
 }
 
+div.sphinxsidebarwrapper li.highligthed {
+    border-radius: 3px;
+    background-color: #fff;
+    color: #0072aa;
+}
+
+div.sphinxsidebarwrapper li.div.sphinxsidebarwrapper li.highligthed {
+    border-radius: 3px;
+    background-color: #fff;
+    color: #0072aa;
+}
+ a {
+    color: #0072aa;
+}
+
+
 div.sphinxsidebar a:hover {
     color: #0095C4;
 }
diff -r 910e293663cb Doc/tools/static/sidebar.js
--- a/Doc/tools/static/sidebar.js	Fri Sep 09 00:05:42 2016 -0700
+++ b/Doc/tools/static/sidebar.js	Fri Sep 09 14:11:24 2016 +0200
@@ -5,7 +5,7 @@
  * This script makes the Sphinx sidebar collapsible and implements intelligent
  * scrolling.
  *
- * .sphinxsidebar contains .sphinxsidebarwrapper.  This script adds in
+ * .sphinxsidebar contains .sphinxsidebarwrappersphinxsidebarwrapper.  This script adds in
  * .sphixsidebar, after .sphinxsidebarwrapper, the #sidebarbutton used to
  * collapse and expand the sidebar.
  *
@@ -162,32 +162,50 @@
   set_position_from_cookie();
 
 
-  /* intelligent scrolling */
-  function scroll_sidebar() {
-    var sidebar_height = sidebarwrapper.height();
-    var viewport_height = get_viewport_height();
-    var offset = sidebar.position()['top'];
-    var wintop = jwindow.scrollTop();
-    var winbot = wintop + viewport_height;
-    var curtop = sidebarwrapper.position()['top'];
-    var curbot = curtop + sidebar_height;
-    // does sidebar fit in window?
-    if (sidebar_height < viewport_height) {
-      // yes: easy case -- always keep at the top
-      sidebarwrapper.css('top', $u.min([$u.max([0, wintop - offset - 10]),
-                            jdocument.height() - sidebar_height - 200]));
+  var headers = $('.body h1, .body h2, .body h3');
+  function findFirstElement() {
+    var i = 0, top;
+    for(; i<headers.length; i++) {
+      top = headers[i].getBoundingClientRect().top;
+      if(top > 0 && top < window.innerHeight) {
+        return headers[i];
+      }
     }
-    else {
-      // no: only scroll if top/bottom edge of sidebar is at
-      // top/bottom edge of window
-      if (curtop > wintop && curbot > winbot) {
-        sidebarwrapper.css('top', $u.max([wintop - offset - 10, 0]));
-      }
-      else if (curtop < wintop && curbot < winbot) {
-        sidebarwrapper.css('top', $u.min([winbot - sidebar_height - offset - 20,
-                              jdocument.height() - sidebar_height - 200]));
+    i = headers.length - 1;
+    for(; i>0; i--) {
+      top = headers[i].getBoundingClientRect().top;
+      if(top < 0) {
+        return headers[i];
       }
     }
   }
-  jwindow.scroll(scroll_sidebar);
+
+  var initial_top = parseInt(sidebarwrapper.position().top, 10);
+  var sidebar_top = initial_top;
+  sidebarwrapper.css('position', 'absolute');
+  var previous;
+
+  jwindow.scroll(function() {
+    var h = findFirstElement();
+    if(h) {
+      var href = $('.headerlink, .headerlink', h).attr('href');
+      var sidebar_link = $('.sphinxsidebar a[href$="'+href+'"]').parent();
+      if(!sidebar_link[0]) {
+        if(previous) {
+          previous.removeClass('highligthed');
+        }
+        sidebarwrapper.css('top', initial_top + 'px');
+        return;
+      }
+      var diff = sidebar_link[0].getBoundingClientRect().top;
+      sidebar_top = Math.max(sidebar_top - diff + 50, initial_top);
+      sidebarwrapper.css('top', sidebar_top + 'px');
+      if(previous) {
+        previous.removeClass('highligthed');
+      }
+      sidebar_link.addClass('highligthed');
+      previous = sidebar_link;
+    }
+
+  });
 });