diff --git a/mod/assign/submission/file/locallib.php b/mod/assign/submission/file/locallib.php
index 5b60450ffa1..8df609bb7b7 100644
--- a/mod/assign/submission/file/locallib.php
+++ b/mod/assign/submission/file/locallib.php
@@ -111,7 +111,7 @@ class assign_submission_file extends assign_submission_plugin {
                            'notchecked');
 
         $name = get_string('acceptedfiletypes', 'assignsubmission_file');
-        $mform->addElement('text', 'assignsubmission_file_filetypes', $name);
+        $mform->addElement('text', 'assignsubmission_file_filetypes', $name, array('size' => '60'));
         $mform->addHelpButton('assignsubmission_file_filetypes', 'acceptedfiletypes', 'assignsubmission_file');
         $mform->setType('assignsubmission_file_filetypes', PARAM_RAW);
         $mform->setDefault('assignsubmission_file_filetypes', $defaultfiletypes);
diff --git a/mod/assign/submission/file/settings.php b/mod/assign/submission/file/settings.php
index f96217fd2c9..c90509e5672 100644
--- a/mod/assign/submission/file/settings.php
+++ b/mod/assign/submission/file/settings.php
@@ -34,7 +34,7 @@ $settings->add(new admin_setting_configtext('assignsubmission_file/maxfiles',
 
 $settings->add(new admin_setting_configtext('assignsubmission_file/filetypes',
                    new lang_string('defaultacceptedfiletypes', 'assignsubmission_file'),
-                   new lang_string('acceptedfiletypes_help', 'assignsubmission_file'), '', PARAM_TEXT));
+                   new lang_string('acceptedfiletypes_help', 'assignsubmission_file'), '', PARAM_TEXT, 60));
 
 if (isset($CFG->maxbytes)) {