diff --git a/tests/scripts/test_workarounds_application.py b/tests/scripts/test_workarounds_application.py
index e6b5221ff..14149da55 100644
--- a/tests/scripts/test_workarounds_application.py
+++ b/tests/scripts/test_workarounds_application.py
@@ -2,8 +2,10 @@
 from multiprocessing import util, Process, Manager
 
 import os
+import pytest
 
 import leapp  # noqa: F401; pylint: disable=unused-import
+from leapp.utils.workarounds import fqdn
 
 
 def test_mp_is_patched():
@@ -29,3 +31,26 @@ def child_fun(_lst):
 def test_mp_workaround_applied():
     if getattr(util, 'os', None) is None:
         assert util.Finalize.__name__ == 'FixedFinalize'
+
+
+@pytest.mark.parametrize(
+    ('input_fqdn', 'valid'),
+    [
+        ('foo.bar.com', True),
+        ('foo\xa0bar.foo.com', False),
+        ('-foo.bar', False),
+        ('foo.bar-', False),
+        ('foo.-bar.1234', False),
+        ('a1.b2.c3', True),
+        ('123.foo.bar', True),
+        ('123.f-o-o.b-a-r', True),
+    ]
+)
+def test_fqdn_is_patched(input_fqdn, valid):
+
+    def getfqdn():
+        return input_fqdn
+
+    fn = fqdn.decorate_getfqdn(getfqdn)
+    expected_fqdn = input_fqdn if valid else 'invalid.hostname'
+    assert fn() == expected_fqdn