diff --git a/lib/externallib.php b/lib/externallib.php
index 571ea0ff745..7dd64ea141a 100644
--- a/lib/externallib.php
+++ b/lib/externallib.php
@@ -987,6 +987,8 @@ class external_settings {
         if ((AJAX_SCRIPT == false) && (CLI_SCRIPT == false) && (WS_SERVER == false)) {
             // For normal pages, the default should match the default for format_text.
             $this->filter = true;
+            // Use pluginfile.php for web requests.
+            $this->file = 'pluginfile.php';
         }
     }