diff --git a/pungi/phases/livemedia_phase.py b/pungi/phases/livemedia_phase.py
index 1060317c..c5f3ec27 100644
--- a/pungi/phases/livemedia_phase.py
+++ b/pungi/phases/livemedia_phase.py
@@ -35,7 +35,7 @@ class LiveMediaPhase(PhaseBase):
         },
         {
             "name": "live_media_release",
-            "expected_types": [str],
+            "expected_types": [str, type(None)],
             "optional": True,
         }
     )
diff --git a/tests/test_livemediaphase.py b/tests/test_livemediaphase.py
index 20ccdfcb..493ffe24 100755
--- a/tests/test_livemediaphase.py
+++ b/tests/test_livemediaphase.py
@@ -14,6 +14,26 @@ from tests.helpers import DummyCompose, PungiTestCase
 
 
 class TestLiveMediaPhase(PungiTestCase):
+
+    def test_global_config_validation(self):
+        compose = DummyCompose(self.topdir, {
+            'live_media_ksurl': 'git://example.com/repo.git#HEAD',
+            'live_media_target': 'f24',
+            'live_media_release': 'RRR',
+            'live_media_version': 'Rawhide',
+        })
+
+        phase = LiveMediaPhase(compose)
+        phase.validate()
+
+    def test_global_config_null_release(self):
+        compose = DummyCompose(self.topdir, {
+            'live_media_release': None,
+        })
+
+        phase = LiveMediaPhase(compose)
+        phase.validate()
+
     @mock.patch('pungi.phases.livemedia_phase.ThreadPool')
     def test_live_media_minimal(self, ThreadPool):
         compose = DummyCompose(self.topdir, {