diff --git a/admin/tool/dataprivacy/db/upgrade.php b/admin/tool/dataprivacy/db/upgrade.php
index 2f52d4857c6..99fd1568ddb 100644
--- a/admin/tool/dataprivacy/db/upgrade.php
+++ b/admin/tool/dataprivacy/db/upgrade.php
@@ -299,5 +299,19 @@ function xmldb_tool_dataprivacy_upgrade($oldversion) {
         upgrade_plugin_savepoint(true, 2018110700, 'tool', 'dataprivacy');
     }
 
+    if ($oldversion < 2018112500) {
+        // Delete orphaned data privacy requests.
+        $sql = "SELECT r.id
+                  FROM {tool_dataprivacy_request} r LEFT JOIN {user} u ON r.userid = u.id
+                 WHERE u.id IS NULL";
+        $orphaned = $DB->get_fieldset_sql($sql);
+
+        if ($orphaned) {
+            $DB->delete_records_list('tool_dataprivacy_request', 'id', $orphaned);
+        }
+
+        upgrade_plugin_savepoint(true, 2018112500, 'tool', 'dataprivacy');
+    }
+
     return true;
 }
diff --git a/admin/tool/dataprivacy/version.php b/admin/tool/dataprivacy/version.php
index d25e4c87960..24cc5a6da51 100644
--- a/admin/tool/dataprivacy/version.php
+++ b/admin/tool/dataprivacy/version.php
@@ -24,6 +24,6 @@
 
 defined('MOODLE_INTERNAL') || die;
 
-$plugin->version   = 2018110900;
+$plugin->version   = 2018112500;
 $plugin->requires  = 2018050800;        // Moodle 3.5dev (Build 2018031600) and upwards.
 $plugin->component = 'tool_dataprivacy';