diff --git a/samples/openapi3/client/petstore/python-aiohttp/petstore_api/models/unnamed_dict_with_additional_model_list_properties.py b/samples/openapi3/client/petstore/python-aiohttp/petstore_api/models/unnamed_dict_with_additional_model_list_properties.py
index a96d8d1f8d3..abd2f06aa8f 100644
--- a/samples/openapi3/client/petstore/python-aiohttp/petstore_api/models/unnamed_dict_with_additional_model_list_properties.py
+++ b/samples/openapi3/client/petstore/python-aiohttp/petstore_api/models/unnamed_dict_with_additional_model_list_properties.py
@@ -55,12 +55,22 @@ class UnnamedDictWithAdditionalModelListProperties(BaseModel):
         """Create an instance of UnnamedDictWithAdditionalModelListProperties from a JSON string"""
         return cls.from_dict(json.loads(json_str))
 
-    def to_dict(self):
-        """Returns the dictionary representation of the model using alias"""
-        _dict = self.model_dump(by_alias=True,
-                          exclude={
-                          },
-                          exclude_none=True)
+    def to_dict(self) -> Dict[str, Any]:
+        """Return the dictionary representation of the model using alias.
+
+        This has the following differences from calling pydantic's
+        `self.model_dump(by_alias=True)`:
+
+        * `None` is only added to the output dict for nullable fields that
+          were set at model initialization. Other fields with value `None`
+          are ignored.
+        """
+        _dict = self.model_dump(
+            by_alias=True,
+            exclude={
+            },
+            exclude_none=True,
+        )
         # override the default output from pydantic by calling `to_dict()` of each value in dict_property (dict of array)
         _field_dict_of_array = {}
         if self.dict_property:
diff --git a/samples/openapi3/client/petstore/python-aiohttp/petstore_api/models/unnamed_dict_with_additional_string_list_properties.py b/samples/openapi3/client/petstore/python-aiohttp/petstore_api/models/unnamed_dict_with_additional_string_list_properties.py
index 17c897d2b56..5fad957d5bf 100644
--- a/samples/openapi3/client/petstore/python-aiohttp/petstore_api/models/unnamed_dict_with_additional_string_list_properties.py
+++ b/samples/openapi3/client/petstore/python-aiohttp/petstore_api/models/unnamed_dict_with_additional_string_list_properties.py
@@ -54,12 +54,22 @@ class UnnamedDictWithAdditionalStringListProperties(BaseModel):
         """Create an instance of UnnamedDictWithAdditionalStringListProperties from a JSON string"""
         return cls.from_dict(json.loads(json_str))
 
-    def to_dict(self):
-        """Returns the dictionary representation of the model using alias"""
-        _dict = self.model_dump(by_alias=True,
-                          exclude={
-                          },
-                          exclude_none=True)
+    def to_dict(self) -> Dict[str, Any]:
+        """Return the dictionary representation of the model using alias.
+
+        This has the following differences from calling pydantic's
+        `self.model_dump(by_alias=True)`:
+
+        * `None` is only added to the output dict for nullable fields that
+          were set at model initialization. Other fields with value `None`
+          are ignored.
+        """
+        _dict = self.model_dump(
+            by_alias=True,
+            exclude={
+            },
+            exclude_none=True,
+        )
         return _dict
 
     @classmethod
diff --git a/samples/openapi3/client/petstore/python/petstore_api/models/unnamed_dict_with_additional_model_list_properties.py b/samples/openapi3/client/petstore/python/petstore_api/models/unnamed_dict_with_additional_model_list_properties.py
index ed29383d86e..4aa1fcbac58 100644
--- a/samples/openapi3/client/petstore/python/petstore_api/models/unnamed_dict_with_additional_model_list_properties.py
+++ b/samples/openapi3/client/petstore/python/petstore_api/models/unnamed_dict_with_additional_model_list_properties.py
@@ -56,13 +56,24 @@ class UnnamedDictWithAdditionalModelListProperties(BaseModel):
         """Create an instance of UnnamedDictWithAdditionalModelListProperties from a JSON string"""
         return cls.from_dict(json.loads(json_str))
 
-    def to_dict(self):
-        """Returns the dictionary representation of the model using alias"""
-        _dict = self.model_dump(by_alias=True,
-                          exclude={
-                            "additional_properties"
-                          },
-                          exclude_none=True)
+    def to_dict(self) -> Dict[str, Any]:
+        """Return the dictionary representation of the model using alias.
+
+        This has the following differences from calling pydantic's
+        `self.model_dump(by_alias=True)`:
+
+        * `None` is only added to the output dict for nullable fields that
+          were set at model initialization. Other fields with value `None`
+          are ignored.
+        * Fields in `self.additional_properties` are added to the output dict.
+        """
+        _dict = self.model_dump(
+            by_alias=True,
+            exclude={
+                "additional_properties",
+            },
+            exclude_none=True,
+        )
         # override the default output from pydantic by calling `to_dict()` of each value in dict_property (dict of array)
         _field_dict_of_array = {}
         if self.dict_property:
diff --git a/samples/openapi3/client/petstore/python/petstore_api/models/unnamed_dict_with_additional_string_list_properties.py b/samples/openapi3/client/petstore/python/petstore_api/models/unnamed_dict_with_additional_string_list_properties.py
index 377fbf4abde..bee320032a9 100644
--- a/samples/openapi3/client/petstore/python/petstore_api/models/unnamed_dict_with_additional_string_list_properties.py
+++ b/samples/openapi3/client/petstore/python/petstore_api/models/unnamed_dict_with_additional_string_list_properties.py
@@ -55,13 +55,24 @@ class UnnamedDictWithAdditionalStringListProperties(BaseModel):
         """Create an instance of UnnamedDictWithAdditionalStringListProperties from a JSON string"""
         return cls.from_dict(json.loads(json_str))
 
-    def to_dict(self):
-        """Returns the dictionary representation of the model using alias"""
-        _dict = self.model_dump(by_alias=True,
-                          exclude={
-                            "additional_properties"
-                          },
-                          exclude_none=True)
+    def to_dict(self) -> Dict[str, Any]:
+        """Return the dictionary representation of the model using alias.
+
+        This has the following differences from calling pydantic's
+        `self.model_dump(by_alias=True)`:
+
+        * `None` is only added to the output dict for nullable fields that
+          were set at model initialization. Other fields with value `None`
+          are ignored.
+        * Fields in `self.additional_properties` are added to the output dict.
+        """
+        _dict = self.model_dump(
+            by_alias=True,
+            exclude={
+                "additional_properties",
+            },
+            exclude_none=True,
+        )
         # puts key-value pairs in additional_properties in the top level
         if self.additional_properties is not None:
             for _key, _value in self.additional_properties.items():