diff --git a/tests/kernel/mbox/mbox_api/boards/qemu_x86_tiny.conf b/tests/kernel/mbox/mbox_api/boards/qemu_x86_tiny.conf
new file mode 100644
index 00000000000..3399758324f
--- /dev/null
+++ b/tests/kernel/mbox/mbox_api/boards/qemu_x86_tiny.conf
@@ -0,0 +1,5 @@
+# Copyright (c) 2021 Intel Corporation
+# SPDX-License-Identifier: Apache-2.0
+
+# Need a little bit more stack space
+CONFIG_TEST_EXTRA_STACKSIZE=256