diff --git a/apachesolr_multisitesearch.module b/apachesolr_multisitesearch.module
index b075b3b..b99384f 100644
--- a/apachesolr_multisitesearch.module
+++ b/apachesolr_multisitesearch.module
@@ -463,3 +463,40 @@ function apachesolr_multisitesearch_apachesolr_delete_index_alter(&$query) {
   // Limit to the current site.
   $query = "($query) AND hash:" . apachesolr_site_hash();
 }
+
+/**
+* Implementation of hook_form_[form_id]_alter().
+*
+* This adds spelling suggestions, retain filters to the search form.
+*/
+function apachesolr_multisitesearch_form_search_form_alter(&$form, $form_state) {
+  if ($form['module']['#value'] == 'apachesolr_multisitesearch') {
+    $response = apachesolr_static_response_cache(NULL, 'apachesolr_multisitesearch');
+    if (variable_get('apachesolr_search_spellcheck', TRUE) && $response) {
+      // Get spellchecker suggestions into an array.
+      if (isset($response->spellcheck->suggestions) && $response->spellcheck->suggestions) {
+        $suggestions = get_object_vars($response->spellcheck->suggestions);
+        if ($suggestions) {
+          // Get the original query and replace words.
+          $query = apachesolr_current_query(NULL, 'apachesolr_multisitesearch');
+
+          foreach ($suggestions as $word => $value) {
+            $replacements[$word] = $value->suggestion[0];
+          }
+          $new_keywords = strtr($query->get_query_basic(), $replacements);
+
+          // Show only if suggestion is different than current query.
+          if ($query->get_query_basic() != $new_keywords) {
+            $form['basic']['suggestion'] = array(
+              '#prefix' => '<div class="spelling-suggestions">',
+              '#suffix' => '</div>',
+              '#type' => 'item',
+              '#title' => t('Did you mean'),
+              '#value' => l($new_keywords, $query->get_path($new_keywords)),
+            );
+          }
+        }
+      }
+    }
+  }
+}