diff --git a/securepages.module b/securepages.module
index 9334b49..9e1e293 100644
--- a/securepages.module
+++ b/securepages.module
@@ -29,6 +29,15 @@ batch'
  * Implements hook_init().
  */
 function securepages_init() {
+  // Secure insecure sessions.
+  global $is_https;
+  if ($is_https && user_is_anonymous()) {
+    $insecure_session = db_query("SELECT 1 FROM {sessions} WHERE sid = :name AND ssid = ''", array(':name' => $_COOKIE[substr(session_name(), 1)]))->fetchField();
+    if ($insecure_session) {
+      drupal_session_regenerate();
+    }
+  }
+
   // Special path for verifying SSL status.
   if ($_GET['q'] == 'admin/structure/securepages/test') {
     if (securepages_is_secure()) {