diff --git a/tests/functional_tests/0004_start_test.py b/tests/functional_tests/0004_start_test.py
index 5193627d..602d31de 100644
--- a/tests/functional_tests/0004_start_test.py
+++ b/tests/functional_tests/0004_start_test.py
@@ -23,6 +23,7 @@
 # POSSIBILITY OF SUCH DAMAGE.
 
 import pytest
+import inspect
 
 
 require_root = pytest.mark.require_root
@@ -62,28 +63,43 @@ def test_02_start_rc_jail(invoke_cli, resource_selector):
 def test_03_create_and_start_nobridge_vnet_jail(release, jail, invoke_cli, nobridge_jail_ip):
     jail = jail('nobridge_jail')
 
-    invoke_cli([
-        'create', '-r', release, '-n', jail.name,
-        f'ip4_addr=lo0|{nobridge_jail_ip}', 'boot=on', 'vnet=on',
-        'interfaces=vnet0:none', 'vnet_default_interface=none',
-        'ip6_addr=vnet0|fe80::2/64', 'defaultrouter6=none',
-        'defaultrouter=none',
-        f'exec_poststart="ifconfig vnet0.$(jls -j ioc-{jail.name} jid) inet6 fe80::1/64"'
-    ])
-
-    assert jail.exists is True
-    assert jail.running is True
-
-    stdout, stderr = jail.run_command(['ifconfig'])
-    assert bool(stderr) is False, f'Ifconfig returned an error: {stderr}'
-    assert 'fe80::2%epair0b' in stdout
-
-    stdout, stderr = jail.run_command(['ifconfig'], jailed=False)
-
-    assert bool(stderr) is False, f'Ifconfig returned an error: {stderr}'
-    assert 'bridge' not in stdout, 'Unexpected bridge was created.'
-    assert f'fe80::1%vnet0.{jail.jid}:' in stdout
-    assert f'description: associated with jail: {jail.name} as nic: epair0b'
-
-    stdout, stderr = jail.run_command(['ping', '-c', '1', f'fe80::2%vnet0.{jail.jid}'], jailed=False)
-    assert bool(stderr) is False, f'Ping returned an error: {stderr}'
+    fd, path = tempfile.mkstemp()
+
+    try:
+        with os.fdopen(fd, 'w') as tmp:
+            tmp.write(inspect.cleandoc("""
+                #!/bin/sh
+                jailname=ioc-$1
+                jid=jls -j $jailname jid
+                iface=vnet0.$jid
+                ifconfig $iface inet6 fe80::1/64
+            """))
+
+        invoke_cli([
+            'create', '-r', release, '-n', jail.name,
+            f'ip4_addr=lo0|{nobridge_jail_ip}', 'boot=on', 'vnet=on',
+            'interfaces=vnet0:none', 'vnet_default_interface=none',
+            'ip6_addr=vnet0|fe80::2/64', 'defaultrouter6=none',
+            'defaultrouter=none',
+            f'exec_poststart="{path} {jail.name}"'
+        ])
+    
+        assert jail.exists is True
+        assert jail.running is True
+    
+        stdout, stderr = jail.run_command(['ifconfig'])
+        assert bool(stderr) is False, f'Ifconfig returned an error: {stderr}'
+        assert 'fe80::2%epair0b' in stdout
+    
+        stdout, stderr = jail.run_command(['ifconfig'], jailed=False)
+    
+        assert bool(stderr) is False, f'Ifconfig returned an error: {stderr}'
+        assert 'bridge' not in stdout, 'Unexpected bridge was created.'
+        assert f'fe80::1%vnet0.{jail.jid}:' in stdout
+        assert f'description: associated with jail: {jail.name} as nic: epair0b'
+    
+        stdout, stderr = jail.run_command(['ping', '-c', '1', f'fe80::2%vnet0.{jail.jid}'], jailed=False)
+        assert bool(stderr) is False, f'Ping returned an error: {stderr}'
+
+    finally:
+        os.remove(path)