diff --git a/lib/classes/encryption.php b/lib/classes/encryption.php
index aff8599e4e5..436d5e2ac5a 100644
--- a/lib/classes/encryption.php
+++ b/lib/classes/encryption.php
@@ -84,8 +84,8 @@ class encryption {
             throw new \moodle_exception('encryption_keyalreadyexists', 'error');
         }
 
-        // Don't make it read-only in Behat or it will fail to clear for future runs.
-        if (defined('BEHAT_SITE_RUNNING')) {
+        // Don't make it read-only in tests or it will fail to clear for future runs.
+        if (defined('BEHAT_SITE_RUNNING') || PHPUNIT_TEST) {
             $chmod = false;
         }
 
diff --git a/lib/tests/encryption_test.php b/lib/tests/encryption_test.php
index 290a8f0413e..8a0932624c8 100644
--- a/lib/tests/encryption_test.php
+++ b/lib/tests/encryption_test.php
@@ -32,26 +32,8 @@ namespace core;
  * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 final class encryption_test extends \advanced_testcase {
-    /**
-     * Clear junk created by tests.
-     */
-    protected function tearDown(): void {
-        global $CFG;
-        $keyfile = encryption::get_key_file(encryption::METHOD_OPENSSL);
-        if (file_exists($keyfile)) {
-            chmod($keyfile, 0700);
-        }
-        $keyfile = encryption::get_key_file(encryption::METHOD_SODIUM);
-        if (file_exists($keyfile)) {
-            chmod($keyfile, 0700);
-        }
-        remove_dir($CFG->dataroot . '/secret');
-        unset($CFG->nokeygeneration);
-    }
 
     protected function setUp(): void {
-        $this->tearDown();
-
         require_once(__DIR__ . '/fixtures/testable_encryption.php');
     }