diff --git a/ajax_facets.install b/ajax_facets.install
index e69de29..74f3111 100644
--- a/ajax_facets.install
+++ b/ajax_facets.install
@@ -0,0 +1,41 @@
+<?php
+
+/**
+ * @file
+ * ajax_facets.install file.
+ */
+
+/**
+ * Implements hook_requirements().
+ */
+function ajax_facets_requirements($phase) {
+  $requirements = array();
+  $t = get_t();
+
+  switch ($phase) {
+    case 'runtime':
+      $description = $t('For now browser ajax history feature works only in HTML5 browsers. If you want to get this feature on HTML4 browsers you need to install libraries module and download history.js library.');
+      $value = $t('Libraries module not installed.');
+
+      if (module_exists('libraries')) {
+        if (!libraries_get_path('history.js')) {
+          $description = $t('For now browser ajax history feature works only in HTML5 browsers. If you want to get this feature on HTML4 browsers you need to download history.js library.');
+          $value = $t('Library history.js not found.');
+        }
+        else {
+          $description = $t('For now browser ajax history feature works both in HTML4 and HTML5 browsers.');
+          $value = $t('Works with history.js library');
+        }
+      }
+
+      $requirements['ajax_facets_message'] = array(
+        'title' => $t('Ajax Facets'),
+        'description' => $description,
+        'value' => $value,
+        'severity' => REQUIREMENT_INFO,
+      );
+      break;
+  }
+
+  return $requirements;
+}
diff --git a/ajax_facets.module b/ajax_facets.module
index 6be08ae..e871353 100644
--- a/ajax_facets.module
+++ b/ajax_facets.module
@@ -93,6 +93,7 @@ function ajax_facets_add_ajax_js($facet) {
   static $included = FALSE;
   if (!$included) {
     $included = TRUE;
+    $history_js_exists = FALSE;
     $module_path = drupal_get_path('module', 'ajax_facets');
     drupal_add_js($module_path . '/misc/ajax_facets.js');
     drupal_add_css($module_path . '/misc/ajax_facets.css');
@@ -104,6 +105,16 @@ function ajax_facets_add_ajax_js($facet) {
     $view_name = '';
     $display_name = '';
 
+    // Add history.js file if exists.
+    if (module_exists('libraries')) {
+      $history_js_path = libraries_get_path('history.js');
+
+      if ($history_js_path) {
+        $history_js_exists = TRUE;
+        drupal_add_js($history_js_path . '/scripts/bundled/html4+html5/jquery.history.js', array('group' => JS_LIBRARY));
+      }
+    }
+
     if (!empty($views)) {
       // Get display from current search.
       if (empty($view_name) || empty($display_name)) {
@@ -125,6 +136,7 @@ function ajax_facets_add_ajax_js($facet) {
       'display_name' => $display_name,
       'facet_field' => $facet['map options']['field']['key'],
       'applyPath' => url($search_path, array('query' => $query)),
+      'isHistoryJsExists' => $history_js_exists,
     );
     drupal_add_js($setting, 'setting');
     drupal_add_library('system', 'drupal.ajax');
diff --git a/misc/ajax_facets.js b/misc/ajax_facets.js
index 731d72c..ef2cf58 100644
--- a/misc/ajax_facets.js
+++ b/misc/ajax_facets.js
@@ -8,6 +8,8 @@
   Drupal.ajax_facets.queryState = null;
   // State of each facet.
   Drupal.ajax_facets.facetQueryState = null;
+  // Determine if it is first page load. Will be reset in Drupal.ajax_facets.initHistoryState.
+  Drupal.ajax_facets.firstLoad = true;
   // HTML ID of element of current facet.
   Drupal.ajax_facets.current_id = null;
   // Current changed facet.
@@ -35,8 +37,7 @@
       if (!Drupal.ajax_facets.queryState) {
         if (settings.facetapi.defaultQuery != undefined && settings.facetapi.defaultQuery) {
           Drupal.ajax_facets.queryState = {'f': settings.facetapi.defaultQuery};
-        }
-        else {
+        } else {
           Drupal.ajax_facets.queryState = {'f': []};
         }
         // We will send original search path to server to get back proper reset links.
@@ -176,8 +177,7 @@
     var facet_values = Drupal.ajax_facets.getFacetValues();
     if (facet_values[settings.facetapi.facets[index]['facetName']] != undefined) {
       $('#' + facetWrapperId + '-wrapper').find('a.reset-link').show();
-    }
-    else {
+    } else {
       $('#' + facetWrapperId + '-wrapper').find('a.reset-link').hide();
     }
 
@@ -185,7 +185,7 @@
       var $facet = $(this).parent().find('[data-facet]').first();
       var facetName = $facet.data('facet');
       Drupal.ajax_facets.excludeCurrentFacet(facetName);
-      Drupal.ajax_facets.sendAjaxQuery($facet);
+      Drupal.ajax_facets.sendAjaxQuery($facet, true);
       event.preventDefault();
     });
   };
@@ -194,9 +194,11 @@
    * Callback for onClick event for widget selectbox.
    */
   Drupal.ajax_facets.processSelectbox = function (event) {
-
     var $this = $(this);
     var facetName = $this.data('facet');
+
+    Drupal.ajax_facets.initHistoryState($this);
+
     if (Drupal.ajax_facets.queryState['f'] != undefined) {
       // Exclude all values for this facet from query.
       Drupal.ajax_facets.excludeCurrentFacet(facetName);
@@ -204,13 +206,12 @@
       /* Default value. */
       if ($this.find(":selected").val() == '_none') {
         delete Drupal.ajax_facets.queryState['f'][Drupal.ajax_facets.queryState['f'].length];
-      }
-      else {
+      } else {
         Drupal.ajax_facets.queryState['f'][Drupal.ajax_facets.queryState['f'].length] = facetName + ':' + $this.find(":selected").val();
       }
     }
 
-    Drupal.ajax_facets.sendAjaxQuery($this);
+    Drupal.ajax_facets.sendAjaxQuery($this, true);
   };
 
   /**
@@ -219,6 +220,9 @@
   Drupal.ajax_facets.processCheckboxes = function (event) {
     var $this = $(this);
     var facetName = $this.data('facet');
+
+    Drupal.ajax_facets.initHistoryState($this);
+
     var facetCheckboxName = $this.attr('name');
     if (Drupal.ajax_facets.queryState['f'] != undefined) {
       var queryNew = new Array();
@@ -250,7 +254,7 @@
       }
     }
 
-    Drupal.ajax_facets.sendAjaxQuery($this);
+    Drupal.ajax_facets.sendAjaxQuery($this, true);
   };
 
   /**
@@ -259,6 +263,9 @@
   Drupal.ajax_facets.processLink = function (event) {
     var $this = $(this);
     var facetName = $this.data('facet');
+
+    Drupal.ajax_facets.initHistoryState($this);
+
     var name_value = $this.data('name') + ':' + $this.data('value');
     if (Drupal.ajax_facets.queryState['f'] != undefined) {
       var queryNew = new Array();
@@ -289,7 +296,7 @@
       }
     }
 
-    Drupal.ajax_facets.sendAjaxQuery($this);
+    Drupal.ajax_facets.sendAjaxQuery($this, true);
     event.preventDefault();
   };
 
@@ -297,6 +304,7 @@
    * Callback for slide event for widget ranges.
    */
   Drupal.ajax_facets.processSlider = function($sliderWrapper, min, max) {
+    Drupal.ajax_facets.initHistoryState($sliderWrapper);
     window.clearTimeout(Drupal.ajax_facets.timer);
     Drupal.ajax_facets.timer = window.setTimeout(function() {
       var facetName = $sliderWrapper.data('facet');
@@ -306,7 +314,7 @@
         Drupal.ajax_facets.queryState['f'][Drupal.ajax_facets.queryState['f'].length] = facetName + ':[' + min + ' TO ' + max + ']';
       }
 
-      Drupal.ajax_facets.sendAjaxQuery($sliderWrapper);
+      Drupal.ajax_facets.sendAjaxQuery($sliderWrapper, true);
     }, 600);
   }
 
@@ -327,7 +335,7 @@
   /**
    * Send ajax.
    */
-  Drupal.ajax_facets.sendAjaxQuery = function ($this) {
+  Drupal.ajax_facets.sendAjaxQuery = function ($this, pushStateNeeded) {
     Drupal.ajax_facets.current_id = $this.attr('id');
     Drupal.ajax_facets.current_facet_name = $this.data('facet');
     Drupal.ajax_facets.beforeAjax();
@@ -343,6 +351,20 @@
       submit : {'ajax_facets' : data}
     };
     var ajax = new Drupal.ajax(false, false, settings);
+    ajax.success = function(response, status) {
+      // Push new state only on successful ajax response.
+      if (pushStateNeeded) {
+        var stateUrl = Drupal.ajax_facets.getFacetsQueryUrl(Drupal.settings.basePath + Drupal.settings.pathPrefix + Drupal.settings.facetapi.searchPath),
+        state = {
+          current_id: Drupal.ajax_facets.current_id,
+          current_facet_name: Drupal.ajax_facets.current_facet_name,
+          facets: Drupal.ajax_facets.queryState['f']
+        };
+        Drupal.ajax_facets.pushState(state, document.title, stateUrl);
+      }
+      // Pass back to original method.
+      Drupal.ajax.prototype.success.call(this, response, status);
+    };
     ajax.eventResponse(ajax, {});
   },
 
@@ -393,6 +415,199 @@
     return viewDomId;
   }
 
+  /**
+   * Returns query string with selected facets.
+   */
+  Drupal.ajax_facets.getFacetsQueryUrl = function (baseUrl) {
+    var query = {
+      'f': []
+    };
+
+    // Clone variable.
+    $.extend(true, query.f, Drupal.ajax_facets.queryState.f);
+
+    // Facetapi module has a bug when facet name encodes twice.
+    // For example to get this facet work 'category:name:pineapple' it should be 'category%253Aname%3Apineapple'.
+    // It means that first ':' was encoded twice. Why we don't patch facetapi? Because a lot of sites have already
+    // used facetapi module and they links (with wrong encoded facets names) has been indexed by search engines
+    // like Bing or Google. So we just bring this behaviour to ajax_facets module.
+    // Encode each facet filter name (it have already encoded once in FacetapiAjaxWidgetCheckboxes::buildListItems()).
+    for (var filter in query.f) {
+      query.f[filter] = encodeURI(query.f[filter]);
+    }
+
+    if (Drupal.ajax_facets.queryState.query) {
+      query.query = Drupal.ajax_facets.queryState.query;
+    }
+
+    if (Drupal.ajax_facets.queryState.order) {
+      query.order = Drupal.ajax_facets.queryState.order;
+      query.sort = Drupal.ajax_facets.queryState.sort;
+    }
+
+    if (Drupal.ajax_facets.queryState.pages) {
+      query.pages = Drupal.ajax_facets.queryState.pages;
+    }
+
+    // Respect existing query parameters in url.
+    // Merge respected parameters with facet parameters recursively without duplicates.
+    $.extend(true, query, Drupal.ajax_facets.simplifyObject(Drupal.ajax_facets.getAdditionalQueryParameters()));
+
+    // Add query string to base url.
+    if (!$.isEmptyObject(query)) {
+      baseUrl += '?' + decodeURIComponent($.param(query));
+    }
+
+    return baseUrl;
+  };
+
+  /**
+   * Returns additional (not facet) query parameters from current url.
+   */
+  Drupal.ajax_facets.getAdditionalQueryParameters = function () {
+    var result = {};
+
+    // If we have GET params.
+    if (window.location.href.indexOf('?') != -1) {
+      var respectedParameters = window.location.href.split('?')[1].split('&');
+
+      // Get all query parameters in array.
+      for (var i = 0; i < respectedParameters.length; i++) {
+        var pair = respectedParameters[i].split('=');
+
+        // Remove brackets from multiple parameter.
+        pair[0] = pair[0].replace('[]', '');
+
+        // We interested only in additional parameters but not in facet parameters.
+        if (pair[0] != 'f') {
+          if (!result[pair[0]]) {
+            result[pair[0]] = [];
+            result[pair[0]].push(pair[1]);
+          } else {
+            result[pair[0]].push(pair[1]);
+          }
+        }
+      }
+    }
+
+    return result;
+  };
+
+  /**
+   * Returns simplified object.
+   *
+   * If object has array property with only one element then that array will be turn into simple value instead of array.
+   */
+  Drupal.ajax_facets.simplifyObject = function (obj) {
+    for (var name in obj) {
+      if (obj[name].length === 1) {
+        obj[name] = obj[name][0];
+      }
+    }
+
+    return obj;
+  };
+
+  /**
+   * Initialize the history state. We only want to do this on the initial page
+   * load but we can't call it until after a facet has been clicked because we
+   * need to communicate which one is being "deactivated" for our ajax success
+   * handler.
+   */
+  Drupal.ajax_facets.initHistoryState = function ($facet) {
+    // Set the initial state only initial page load.
+    if (Drupal.ajax_facets.firstLoad) {
+      Drupal.ajax_facets.firstLoad = false;
+
+      // If history.js available - use it.
+      if (Drupal.settings.facetapi.isHistoryJsExists) {
+        History.replaceState({
+          current_id: $facet.attr('id'),
+          current_facet_name: $facet.data('facet'),
+          facets: Drupal.ajax_facets.queryState['f']
+        }, null, null);
+      } else {
+        // Fallback to HTML5 history object.
+        if (typeof history.replaceState != 'undefined') {
+          history.replaceState({
+            current_id: $facet.attr('id'),
+            current_facet_name: $facet.data('facet'),
+            facets: Drupal.ajax_facets.queryState['f']
+          }, null, null);
+        }
+      }
+    }
+  };
+
+  /**
+   * Pushes new state to browser history.
+   *
+   * History.js library fires "statechange" event even on API push/replace calls.
+   * So before pushing new state to history we should unbind from this event and after bind again.
+   */
+  Drupal.ajax_facets.pushState = function (state, title, stateUrl) {
+    // If history.js available - use it.
+    if (Drupal.settings.facetapi.isHistoryJsExists) {
+      var $window = $(window);
+
+      $window.unbind('statechange', Drupal.ajax_facets.reactOnStateChange);
+      History.pushState(state, title, stateUrl);
+      $window.bind('statechange', Drupal.ajax_facets.reactOnStateChange);
+    } else {
+      // Fallback to HTML5 history object.
+      if (typeof history.pushState != 'undefined') {
+        history.pushState(state, title, stateUrl);
+      }
+    }
+  };
+
+  /**
+   * Callback for back/forward browser buttons.
+   */
+  Drupal.ajax_facets.reactOnStateChange = function () {
+    var state = null,
+      facets = [],
+      current_id = '';
+
+    // If history.js available - use it.
+    if (Drupal.settings.facetapi.isHistoryJsExists) {
+      state = History.getState();
+
+      facets = state.data.facets;
+      current_id = state.data.current_id;
+    } else {
+      // Fallback to HTML5 history object.
+      if (typeof history.pushState != 'undefined') {
+        state = history.state;
+
+        facets = state.facets;
+        current_id = state.current_id;
+      }
+    }
+
+    Drupal.ajax_facets.queryState['f'] = facets;
+    Drupal.ajax_facets.sendAjaxQuery($('#' + current_id), false);
+  };
+
+  // If user opened new page and then clicked browser's back button then would not be fired "statechange" event.
+  // So we need to bind on 'statechange' event and react only once.
+  // All farther work does Drupal.ajax_facets.pushState() function.
+  // If history.js Adapter available - use it to bind "statechange" event.
+  if (typeof History.Adapter != 'undefined') {
+    History.Adapter.bind(window, 'statechange', function () {
+      if (Drupal.ajax_facets.firstLoad) {
+        Drupal.ajax_facets.reactOnStateChange();
+      }
+    });
+  } else {
+    // Fallback to default HTML5 event.
+    window.onpopstate = function () {
+      if (Drupal.ajax_facets.firstLoad) {
+        Drupal.ajax_facets.reactOnStateChange();
+      }
+    };
+  }
+
   if (Drupal.ajax) {
     // Command for process search results and facets by ajax.
     Drupal.ajax.prototype.commands.ajax_facets_update_content = function(ajax, response) {