diff --git a/lib/datalib.php b/lib/datalib.php
index dd562022429..af096d4baf3 100644
--- a/lib/datalib.php
+++ b/lib/datalib.php
@@ -1992,6 +1992,9 @@ function user_accesstime_log($courseid=0) {
         if (defined('MDL_PERFDB')) { global $PERF ; $PERF->dbqueries++;};
 
         $remoteaddr = getremoteaddr();
+        if (empty($remoteaddr)) {
+            $remoteaddr = '0.0.0.0';
+        }
         if ($db->Execute("UPDATE {$CFG->prefix}user
                              SET lastip = '$remoteaddr', lastaccess = $timenow
                            WHERE id = $USER->id")) {
diff --git a/lib/moodlelib.php b/lib/moodlelib.php
index 69a6d5b5545..b86ef8cca76 100644
--- a/lib/moodlelib.php
+++ b/lib/moodlelib.php
@@ -2968,6 +2968,9 @@ function create_user_record($username, $password, $auth='manual') {
     }
     $newuser->confirmed = 1;
     $newuser->lastip = getremoteaddr();
+    if (empty($newuser->lastip)) {
+        $newuser->lastip = '0.0.0.0';
+    }
     $newuser->timemodified = time();
     $newuser->mnethostid = $CFG->mnet_localhost_id;
 
@@ -3137,6 +3140,9 @@ function guest_user() {
         $newuser->confirmed = 1;
         $newuser->lang = $CFG->lang;
         $newuser->lastip = getremoteaddr();
+        if (empty($newuser->lastip)) {
+            $newuser->lastip = '0.0.0.0';
+        }
     }
 
     return $newuser;