diff --git a/aiopenapi3/v30/servers.py b/aiopenapi3/v30/servers.py
index d269737f..8acdb68f 100644
--- a/aiopenapi3/v30/servers.py
+++ b/aiopenapi3/v30/servers.py
@@ -17,6 +17,13 @@ class ServerVariable(ObjectExtended):
     default: Optional[str] = Field(...)
     description: Optional[str] = Field(default=None)
 
+    @model_validator(mode="after")
+    def validate_ServerVariable(cls, s: "ServerVariable"):
+        assert isinstance(s.enum, (list, None.__class__))
+        # default value must be in enum
+        assert s.default in (s.enum or [s.default])
+        return s
+
 
 class Server(ObjectExtended):
     """
diff --git a/aiopenapi3/v31/servers.py b/aiopenapi3/v31/servers.py
index 2c401019..c16a0a50 100644
--- a/aiopenapi3/v31/servers.py
+++ b/aiopenapi3/v31/servers.py
@@ -21,7 +21,7 @@ class ServerVariable(ObjectExtended):
     def validate_ServerVariable(cls, s: "ServerVariable"):
         assert isinstance(s.enum, (list, None.__class__))
         # default value must be in enum
-        assert s.default in (s.enum or [None])
+        assert s.default in (s.enum or [s.default])
         return s
 
 
diff --git a/tests/conftest.py b/tests/conftest.py
index 3bf7969c..63ab3308 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -56,7 +56,7 @@ def schema(self):
         return getattr(getattr(aiopenapi3, f"v{self.major}{self.minor}"), "Schema")
 
 
-@pytest.fixture(scope="session", params=[_Version(3, 0, 3), _Version(3, 1, 0)])
+@pytest.fixture(scope="session", params=[_Version(3, 0, 3), _Version(3, 1, 0)], ids=("v30", "v31"))
 def openapi_version(request):
     return request.param
 
@@ -74,7 +74,9 @@ def __str__(self):
             return f'swagger: "{self.major}.{self.minor}"'
 
 
-@pytest.fixture(scope="session", params=[_VersionS(2, 0), _VersionS(3, 0, 3), _VersionS(3, 1, 0)])
+@pytest.fixture(
+    scope="session", params=[_VersionS(2, 0), _VersionS(3, 0, 3), _VersionS(3, 1, 0)], ids=("v20", "v30", "v31")
+)
 def api_version(request):
     return request.param
 
@@ -474,10 +476,10 @@ def with_schema_baseurl_v20():
 
 
 @pytest.fixture
-def with_paths_servers():
-    yield _get_parsed_yaml("paths-servers.yaml")
+def with_paths_servers(openapi_version):
+    yield _get_parsed_yaml("paths-servers.yaml", openapi_version)
 
 
 @pytest.fixture
-def with_paths_server_variables():
-    yield _get_parsed_yaml("paths-server-variables.yaml")
+def with_paths_server_variables(openapi_version):
+    yield _get_parsed_yaml("paths-server-variables.yaml", openapi_version)