diff --git a/tests/functional/arm/test_aspeed_ast2600_buildroot.py b/tests/functional/arm/test_aspeed_ast2600_buildroot.py
index 51f2676c90..575a5f6414 100755
--- a/tests/functional/arm/test_aspeed_ast2600_buildroot.py
+++ b/tests/functional/arm/test_aspeed_ast2600_buildroot.py
@@ -9,8 +9,8 @@ import time
 import tempfile
 import subprocess
 
-from qemu_test import Asset
 from aspeed import AspeedTest
+from qemu_test import Asset
 from qemu_test import exec_command_and_wait_for_pattern, skipIfMissingCommands
 
 
@@ -66,21 +66,18 @@ class AST2600Machine(AspeedTest):
          'images/ast2600-evb/buildroot-2023.02-tpm/flash.img'),
         'a46009ae8a5403a0826d607215e731a8c68d27c14c41e55331706b8f9c7bd997')
 
-    @skipIfMissingCommands('swtpm')
-    def test_arm_ast2600_evb_buildroot_tpm(self):
-        self.set_machine('ast2600-evb')
-
+    def _test_arm_ast2600_evb_buildroot_tpm(self, tpmstate_dir):
         image_path = self.ASSET_BR2_202302_AST2600_TPM_FLASH.fetch()
 
-        tpmstate_dir = tempfile.TemporaryDirectory(prefix="qemu_")
-        socket = os.path.join(tpmstate_dir.name, 'swtpm-socket')
+        socket = os.path.join(tpmstate_dir, 'swtpm-socket')
 
         # We must put the TPM state dir in /tmp/, not the build dir,
         # because some distros use AppArmor to lock down swtpm and
         # restrict the set of locations it can access files in.
         subprocess.run(['swtpm', 'socket', '-d', '--tpm2',
-                        '--tpmstate', f'dir={tpmstate_dir.name}',
-                        '--ctrl', f'type=unixio,path={socket}'])
+                        '--tpmstate', f'dir={tpmstate_dir}',
+                        '--ctrl', f'type=unixio,path={socket}'],
+                       check=True)
 
         self.vm.add_args('-chardev', f'socket,id=chrtpm,path={socket}')
         self.vm.add_args('-tpmdev', 'emulator,id=tpm0,chardev=chrtpm')
@@ -97,6 +94,12 @@ class AST2600Machine(AspeedTest):
 
         self.do_test_arm_aspeed_buildroot_poweroff()
 
+    @skipIfMissingCommands('swtpm')
+    def test_arm_ast2600_evb_buildroot_tpm(self):
+        self.set_machine('ast2600-evb')
+        with tempfile.TemporaryDirectory(prefix="qemu_") as tpmstate_dir:
+            self._test_arm_ast2600_evb_buildroot_tpm(tpmstate_dir)
+
 
 if __name__ == '__main__':
     AspeedTest.main()