diff --git a/lib/sessionlib.php b/lib/sessionlib.php
index 2fb6f32dadd..80525173786 100644
--- a/lib/sessionlib.php
+++ b/lib/sessionlib.php
@@ -41,13 +41,13 @@ function session_get_instance() {
 
     static $session = null;
 
-    if (!defined('NO_MOODLE_COOKIES')) {
-        // Moodle session was not initialised yet in lib/setup.php.
-        $session = new emergency_session();
-        return $session;
-    }
-
     if (is_null($session)) {
+        if (!defined('NO_MOODLE_COOKIES') or empty($DB)) {
+            // Moodle was not initialised properly in lib/setup.php.
+            $session = new emergency_session();
+            return $session;
+        }
+
         if (empty($CFG->sessiontimeout)) {
             $CFG->sessiontimeout = 7200;
         }