diff --git a/lib/moodlelib.php b/lib/moodlelib.php
index 3cbd8604a5b..d78d3de4bfc 100644
--- a/lib/moodlelib.php
+++ b/lib/moodlelib.php
@@ -2057,7 +2057,12 @@ function require_logout() {
         error_log('MoodleSessionTest cookie could not be set in moodlelib.php:'.__LINE__);
         error_log('Headers were already sent in file: '.$file.' on line '.$line);
     } else {
-        setcookie('MoodleSessionTest'.$CFG->sessioncookie, '', time() - 3600, $CFG->sessioncookiepath, '', $CFG->cookiesecure, $CFG->cookiehttponly);
+        if (function_exists('array_fill_keys')) {
+            //PHP 5.2.0
+            setcookie('MoodleSessionTest'.$CFG->sessioncookie, '', time() - 3600, $CFG->sessioncookiepath, '', $CFG->cookiesecure, $CFG->cookiehttponly);
+        } else {
+            setcookie('MoodleSessionTest'.$CFG->sessioncookie, '', time() - 3600, $CFG->sessioncookiepath, '', $CFG->cookiesecure);
+        }
     }
 
     unset($_SESSION['USER']);
@@ -7751,8 +7756,14 @@ function report_session_error() {
     moodle_setlocale();
 
     //clear session cookies
-    setcookie('MoodleSession'.$CFG->sessioncookie, '', time() - 3600, $CFG->sessioncookiepath, '', $CFG->cookiesecure, $CFG->cookiehttponly);
-    setcookie('MoodleSessionTest'.$CFG->sessioncookie, '', time() - 3600, $CFG->sessioncookiepath, '', $CFG->cookiesecure, $CFG->cookiehttponly);
+    if (function_exists('array_fill_keys')) {
+        //PHP 5.2.0
+        setcookie('MoodleSession'.$CFG->sessioncookie, '', time() - 3600, $CFG->sessioncookiepath, '', $CFG->cookiesecure, $CFG->cookiehttponly);
+        setcookie('MoodleSessionTest'.$CFG->sessioncookie, '', time() - 3600, $CFG->sessioncookiepath, '', $CFG->cookiesecure, $CFG->cookiehttponly);
+    } else {
+        setcookie('MoodleSession'.$CFG->sessioncookie, '', time() - 3600, $CFG->sessioncookiepath, '', $CFG->cookiesecure);
+        setcookie('MoodleSessionTest'.$CFG->sessioncookie, '', time() - 3600, $CFG->sessioncookiepath, '', $CFG->cookiesecure);
+    }
     //increment database error counters
     if (isset($CFG->session_error_counter)) {
         set_config('session_error_counter', 1 + $CFG->session_error_counter);
diff --git a/lib/setup.php b/lib/setup.php
index 6b0a2c8d022..0923afb4576 100644
--- a/lib/setup.php
+++ b/lib/setup.php
@@ -517,7 +517,12 @@ global $HTTPSPAGEREQUIRED;
 
     if (empty($nomoodlecookie)) {
         session_name('MoodleSession'.$CFG->sessioncookie);
-        session_set_cookie_params(0, $CFG->sessioncookiepath, '', $CFG->cookiesecure, $CFG->cookiehttponly);
+        if (function_exists('array_fill_keys')) {
+            //PHP 5.2.0
+            session_set_cookie_params(0, $CFG->sessioncookiepath, '', $CFG->cookiesecure, $CFG->cookiehttponly);
+        } else {
+            session_set_cookie_params(0, $CFG->sessioncookiepath, '', $CFG->cookiesecure);
+        }
         @session_start();
         if (! isset($_SESSION['SESSION'])) {
             $_SESSION['SESSION'] = new object;
@@ -525,7 +530,12 @@ global $HTTPSPAGEREQUIRED;
             if (!empty($_COOKIE['MoodleSessionTest'.$CFG->sessioncookie])) {
                 $_SESSION['SESSION']->has_timed_out = true;
             }
-            setcookie('MoodleSessionTest'.$CFG->sessioncookie, $_SESSION['SESSION']->session_test, 0, $CFG->sessioncookiepath, '', $CFG->cookiesecure, $CFG->cookiehttponly);
+            if (function_exists('array_fill_keys')) {
+                //PHP 5.2.0
+                setcookie('MoodleSessionTest'.$CFG->sessioncookie, $_SESSION['SESSION']->session_test, 0, $CFG->sessioncookiepath, '', $CFG->cookiesecure, $CFG->cookiehttponly);
+            } else {
+                setcookie('MoodleSessionTest'.$CFG->sessioncookie, $_SESSION['SESSION']->session_test, 0, $CFG->sessioncookiepath, '', $CFG->cookiesecure);
+            }
             $_COOKIE['MoodleSessionTest'.$CFG->sessioncookie] = $_SESSION['SESSION']->session_test;
         }
         if (! isset($_SESSION['USER']))    {