diff --git a/lib/external/tests/external_api_test.php b/lib/external/tests/external_api_test.php
index 87365f0e48a..915831892ef 100644
--- a/lib/external/tests/external_api_test.php
+++ b/lib/external/tests/external_api_test.php
@@ -297,6 +297,7 @@ class external_api_test extends \advanced_testcase {
     /**
      * Test \core_external\external_api::external_function_info.
      *
+     * @runInSeparateProcess
      * @dataProvider all_external_info_provider
      * @covers \core_external\external_api::external_function_info
      * @param \stdClass $definition