diff --git a/src/models/config.py b/src/models/config.py
index c4efa404..44395e6f 100644
--- a/src/models/config.py
+++ b/src/models/config.py
@@ -145,8 +145,8 @@ class ServiceConfiguration(ConfigurationBase):
     workers: PositiveInt = 1
     color_log: bool = True
     access_log: bool = True
-    tls_config: TLSConfiguration = TLSConfiguration()
-    cors: CORSConfiguration = CORSConfiguration()
+    tls_config: TLSConfiguration = Field(default_factory=TLSConfiguration)
+    cors: CORSConfiguration = Field(default_factory=CORSConfiguration)
 
     @model_validator(mode="after")
     def check_service_configuration(self) -> Self:
@@ -371,7 +371,7 @@ class JwkConfiguration(ConfigurationBase):
     """JWK configuration."""
 
     url: AnyHttpUrl
-    jwt_configuration: JwtConfiguration = JwtConfiguration()
+    jwt_configuration: JwtConfiguration = Field(default_factory=JwtConfiguration)
 
 
 class AuthenticationConfiguration(ConfigurationBase):
@@ -458,12 +458,14 @@ class Configuration(ConfigurationBase):
     service: ServiceConfiguration
     llama_stack: LlamaStackConfiguration
     user_data_collection: UserDataCollection
-    database: DatabaseConfiguration = DatabaseConfiguration()
-    mcp_servers: list[ModelContextProtocolServer] = []
-    authentication: AuthenticationConfiguration = AuthenticationConfiguration()
+    database: DatabaseConfiguration = Field(default_factory=DatabaseConfiguration)
+    mcp_servers: list[ModelContextProtocolServer] = Field(default_factory=list)
+    authentication: AuthenticationConfiguration = Field(
+        default_factory=AuthenticationConfiguration
+    )
     authorization: Optional[AuthorizationConfiguration] = None
     customization: Optional[Customization] = None
-    inference: InferenceConfiguration = InferenceConfiguration()
+    inference: InferenceConfiguration = Field(default_factory=InferenceConfiguration)
 
     def dump(self, filename: str = "configuration.json") -> None:
         """Dump actual configuration into JSON file."""
diff --git a/tests/unit/models/config/test_authentication_configuration.py b/tests/unit/models/config/test_authentication_configuration.py
index 481a5712..8e37c687 100644
--- a/tests/unit/models/config/test_authentication_configuration.py
+++ b/tests/unit/models/config/test_authentication_configuration.py
@@ -142,6 +142,7 @@ def test_authentication_configuration_module_unsupported() -> None:
 
 def test_authentication_configuration_in_config() -> None:
     """Test the authentication configuration in main config."""
+    # pylint: disable=no-member
     cfg = Configuration(
         name="test_name",
         service=ServiceConfiguration(),
diff --git a/tests/unit/models/config/test_tls_configuration.py b/tests/unit/models/config/test_tls_configuration.py
index aafe0389..63633f42 100644
--- a/tests/unit/models/config/test_tls_configuration.py
+++ b/tests/unit/models/config/test_tls_configuration.py
@@ -22,6 +22,7 @@ def test_tls_configuration() -> None:
 
 def test_tls_configuration_in_service_configuration() -> None:
     """Test the TLS configuration in service configuration."""
+    # pylint: disable=no-member
     cfg = ServiceConfiguration(
         tls_config=TLSConfiguration(
             tls_certificate_path=Path("tests/configuration/server.crt"),