diff --git a/tests/test_hub_zone.py b/tests/test_hub_zone.py
index 1c804d4..23b8e16 100644
--- a/tests/test_hub_zone.py
+++ b/tests/test_hub_zone.py
@@ -2,6 +2,7 @@
 
 import pathlib
 
+from mudlib.portal import Portal
 from mudlib.zones import load_zone
 
 
@@ -28,7 +29,7 @@ def test_hub_zone_has_portals():
     zone = load_zone(hub_path)
 
     # Find portals in zone contents
-    portals = [obj for obj in zone._contents if obj.__class__.__name__ == "Portal"]
+    portals = [obj for obj in zone._contents if isinstance(obj, Portal)]
     assert len(portals) == 3
 
     # Check that we have portals to each target zone
@@ -43,7 +44,7 @@ def test_hub_zone_portals_at_correct_positions():
 
     zone = load_zone(hub_path)
 
-    portals = [obj for obj in zone._contents if obj.__class__.__name__ == "Portal"]
+    portals = [obj for obj in zone._contents if isinstance(obj, Portal)]
 
     # North portal to overworld at (7, 0)
     overworld_portal = [p for p in portals if p.target_zone == "overworld"][0]
diff --git a/tests/test_tutorial_zones.py b/tests/test_tutorial_zones.py
index e19bd31..5f46c24 100644
--- a/tests/test_tutorial_zones.py
+++ b/tests/test_tutorial_zones.py
@@ -2,6 +2,7 @@
 
 import pathlib
 
+from mudlib.portal import Portal
 from mudlib.zones import load_zone
 
 
@@ -59,7 +60,7 @@ def test_flower_has_portal_to_treehouse():
     zone = load_zone(flower_path)
 
     # Find portals in zone contents
-    portals = [obj for obj in zone._contents if obj.__class__.__name__ == "Portal"]
+    portals = [obj for obj in zone._contents if isinstance(obj, Portal)]
     assert len(portals) == 1
 
     portal = portals[0]
@@ -93,7 +94,7 @@ def test_treehouse_has_portal_to_overworld():
     zone = load_zone(treehouse_path)
 
     # Find portals
-    portals = [obj for obj in zone._contents if obj.__class__.__name__ == "Portal"]
+    portals = [obj for obj in zone._contents if isinstance(obj, Portal)]
 
     # Find the overworld portal
     overworld_portals = [p for p in portals if p.target_zone == "overworld"]
@@ -113,7 +114,7 @@ def test_treehouse_has_portal_to_hub():
     zone = load_zone(treehouse_path)
 
     # Find portals
-    portals = [obj for obj in zone._contents if obj.__class__.__name__ == "Portal"]
+    portals = [obj for obj in zone._contents if isinstance(obj, Portal)]
 
     # Find the hub portal
     hub_portals = [p for p in portals if p.target_zone == "hub"]
diff --git a/tests/test_zone_export.py b/tests/test_zone_export.py
index ad7356d..693065e 100644
--- a/tests/test_zone_export.py
+++ b/tests/test_zone_export.py
@@ -195,9 +195,7 @@ def test_export_zone_with_portals_round_trip():
         assert loaded.height == zone.height
 
         # Verify portals were loaded correctly
-        portals = [
-            obj for obj in loaded._contents if obj.__class__.__name__ == "Portal"
-        ]
+        portals = [obj for obj in loaded._contents if isinstance(obj, Portal)]
         assert len(portals) == 2
 
         # Sort by y coordinate for consistent ordering
diff --git a/tests/test_zone_loading.py b/tests/test_zone_loading.py
index 7ddf2fc..9611985 100644
--- a/tests/test_zone_loading.py
+++ b/tests/test_zone_loading.py
@@ -3,6 +3,7 @@
 import pathlib
 import tempfile
 
+from mudlib.portal import Portal
 from mudlib.zones import load_zone, load_zones
 
 
@@ -254,7 +255,7 @@ label = "forest path"
         zone = load_zone(temp_path)
 
         # Find portals in zone contents
-        portals = [obj for obj in zone._contents if obj.__class__.__name__ == "Portal"]
+        portals = [obj for obj in zone._contents if isinstance(obj, Portal)]
         assert len(portals) == 2
 
         # Check first portal (tavern door at 5,3)
@@ -307,7 +308,7 @@ rows = [
         zone = load_zone(temp_path)
 
         # Should have no portals
-        portals = [obj for obj in zone._contents if obj.__class__.__name__ == "Portal"]
+        portals = [obj for obj in zone._contents if isinstance(obj, Portal)]
         assert len(portals) == 0
     finally:
         temp_path.unlink()
@@ -343,7 +344,7 @@ aliases = ["gateway", "gate", "portal"]
     try:
         zone = load_zone(temp_path)
 
-        portals = [obj for obj in zone._contents if obj.__class__.__name__ == "Portal"]
+        portals = [obj for obj in zone._contents if isinstance(obj, Portal)]
         assert len(portals) == 1
 
         portal = portals[0]
@@ -361,7 +362,7 @@ def test_tavern_has_portal_to_hub():
     zone = load_zone(tavern_path)
 
     # Find portals in zone
-    portals = [obj for obj in zone._contents if obj.__class__.__name__ == "Portal"]
+    portals = [obj for obj in zone._contents if isinstance(obj, Portal)]
     assert len(portals) == 1
 
     # Check portal is at the door (4, 5) and leads to hub