diff --git a/examples/generate-python-pydantic-models/__snapshots__/index.spec.ts.snap b/examples/generate-python-pydantic-models/__snapshots__/index.spec.ts.snap
index 3caa7f420b..6a9edff398 100644
--- a/examples/generate-python-pydantic-models/__snapshots__/index.spec.ts.snap
+++ b/examples/generate-python-pydantic-models/__snapshots__/index.spec.ts.snap
@@ -3,11 +3,11 @@
 exports[`Should be able to render python models and should log expected output to console: class-model 1`] = `
 Array [
   "class Root(BaseModel): 
-  optional_field: Optional[str] = Field(description='''this field is optional''', default=None, alias='''optionalField''')
-  required_field: str = Field(description='''this field is required''', alias='''requiredField''')
-  no_description: Optional[str] = Field(default=None, alias='''noDescription''')
+  optional_field: Optional[str] = Field(description='''this field is optional''', default=None)
+  required_field: str = Field(description='''this field is required''')
+  no_description: Optional[str] = Field(default=None)
   options: Optional[Options.Options] = Field(default=None)
-  content_type: Optional[str] = Field(default=None, alias='''content-type''')
+  content_type: Optional[str] = Field(default=None)
 ",
 ]
 `;
diff --git a/src/generators/python/presets/Pydantic.ts b/src/generators/python/presets/Pydantic.ts
index fb0fff7e38..4627d82857 100644
--- a/src/generators/python/presets/Pydantic.ts
+++ b/src/generators/python/presets/Pydantic.ts
@@ -57,9 +57,6 @@ const PYTHON_PYDANTIC_CLASS_PRESET: ClassPresetType<PythonOptions> = {
     if (!property.required) {
       decoratorArgs.push('default=None');
     }
-    if (property.propertyName !== property.unconstrainedPropertyName) {
-      decoratorArgs.push(`alias='''${property.unconstrainedPropertyName}'''`);
-    }
 
     return `${propertyName}: ${type} = Field(${decoratorArgs.join(', ')})`;
   },
@@ -101,6 +98,8 @@ def custom_serializer(self, handler):
 @model_validator(mode='before')
 @classmethod
 def unwrap_${dictionaryModel?.propertyName}(cls, data):
+  if not isinstance(data, dict):
+    data = data.model_dump()
   json_properties = list(data.keys())
   known_object_properties = [${allProperties
     .map((value) => `'${value}'`)
@@ -113,11 +112,11 @@ def unwrap_${dictionaryModel?.propertyName}(cls, data):
   known_json_properties = [${Object.values(model.properties)
     .map((value) => `'${value.unconstrainedPropertyName}'`)
     .join(', ')}]
-  ${dictionaryModel?.propertyName} = {}
+  ${dictionaryModel?.propertyName} = data.get('${dictionaryModel?.propertyName}', {})
   for obj_key in list(data.keys()):
     if not known_json_properties.__contains__(obj_key):
       ${dictionaryModel?.propertyName}[obj_key] = data.pop(obj_key, None)
-  data['${dictionaryModel?.unconstrainedPropertyName}'] = ${dictionaryModel?.propertyName}
+  data['${dictionaryModel?.propertyName}'] = ${dictionaryModel?.propertyName}
   return data
 ${content}`;
   }
diff --git a/test/generators/python/presets/__snapshots__/Pydantic.spec.ts.snap b/test/generators/python/presets/__snapshots__/Pydantic.spec.ts.snap
index 5b3293d316..d4b6556fed 100644
--- a/test/generators/python/presets/__snapshots__/Pydantic.spec.ts.snap
+++ b/test/generators/python/presets/__snapshots__/Pydantic.spec.ts.snap
@@ -6,7 +6,7 @@ exports[`PYTHON_PYDANTIC_PRESET should render pydantic for class 1`] = `
     multi
     line
     description''', default=None)
-  additional_properties: Optional[dict[str, Any]] = Field(exclude=True, default=None, alias='''additionalProperties''')
+  additional_properties: Optional[dict[str, Any]] = Field(exclude=True, default=None)
 
   @model_serializer(mode='wrap')
   def custom_serializer(self, handler):
@@ -23,6 +23,8 @@ exports[`PYTHON_PYDANTIC_PRESET should render pydantic for class 1`] = `
   @model_validator(mode='before')
   @classmethod
   def unwrap_additional_properties(cls, data):
+    if not isinstance(data, dict):
+      data = data.model_dump()
     json_properties = list(data.keys())
     known_object_properties = ['prop', 'additional_properties']
     unknown_object_properties = [element for element in json_properties if element not in known_object_properties]
@@ -31,11 +33,11 @@ exports[`PYTHON_PYDANTIC_PRESET should render pydantic for class 1`] = `
       return data
   
     known_json_properties = ['prop', 'additionalProperties']
-    additional_properties = {}
+    additional_properties = data.get('additional_properties', {})
     for obj_key in list(data.keys()):
       if not known_json_properties.__contains__(obj_key):
         additional_properties[obj_key] = data.pop(obj_key, None)
-    data['additionalProperties'] = additional_properties
+    data['additional_properties'] = additional_properties
     return data
 
 "
@@ -44,8 +46,8 @@ exports[`PYTHON_PYDANTIC_PRESET should render pydantic for class 1`] = `
 exports[`PYTHON_PYDANTIC_PRESET should render union to support Python < 3.10 1`] = `
 Array [
   "class UnionTest(BaseModel): 
-  union_test: Optional[Union[Union1.Union1, Union2.Union2]] = Field(default=None, alias='''unionTest''')
-  additional_properties: Optional[dict[str, Any]] = Field(exclude=True, default=None, alias='''additionalProperties''')
+  union_test: Optional[Union[Union1.Union1, Union2.Union2]] = Field(default=None)
+  additional_properties: Optional[dict[str, Any]] = Field(exclude=True, default=None)
 
   @model_serializer(mode='wrap')
   def custom_serializer(self, handler):
@@ -62,6 +64,8 @@ Array [
   @model_validator(mode='before')
   @classmethod
   def unwrap_additional_properties(cls, data):
+    if not isinstance(data, dict):
+      data = data.model_dump()
     json_properties = list(data.keys())
     known_object_properties = ['union_test', 'additional_properties']
     unknown_object_properties = [element for element in json_properties if element not in known_object_properties]
@@ -70,17 +74,17 @@ Array [
       return data
   
     known_json_properties = ['unionTest', 'additionalProperties']
-    additional_properties = {}
+    additional_properties = data.get('additional_properties', {})
     for obj_key in list(data.keys()):
       if not known_json_properties.__contains__(obj_key):
         additional_properties[obj_key] = data.pop(obj_key, None)
-    data['additionalProperties'] = additional_properties
+    data['additional_properties'] = additional_properties
     return data
 
 ",
   "class Union1(BaseModel): 
-  test_prop1: Optional[str] = Field(default=None, alias='''testProp1''')
-  additional_properties: Optional[dict[str, Any]] = Field(exclude=True, default=None, alias='''additionalProperties''')
+  test_prop1: Optional[str] = Field(default=None)
+  additional_properties: Optional[dict[str, Any]] = Field(exclude=True, default=None)
 
   @model_serializer(mode='wrap')
   def custom_serializer(self, handler):
@@ -97,6 +101,8 @@ Array [
   @model_validator(mode='before')
   @classmethod
   def unwrap_additional_properties(cls, data):
+    if not isinstance(data, dict):
+      data = data.model_dump()
     json_properties = list(data.keys())
     known_object_properties = ['test_prop1', 'additional_properties']
     unknown_object_properties = [element for element in json_properties if element not in known_object_properties]
@@ -105,17 +111,17 @@ Array [
       return data
   
     known_json_properties = ['testProp1', 'additionalProperties']
-    additional_properties = {}
+    additional_properties = data.get('additional_properties', {})
     for obj_key in list(data.keys()):
       if not known_json_properties.__contains__(obj_key):
         additional_properties[obj_key] = data.pop(obj_key, None)
-    data['additionalProperties'] = additional_properties
+    data['additional_properties'] = additional_properties
     return data
 
 ",
   "class Union2(BaseModel): 
-  test_prop2: Optional[str] = Field(default=None, alias='''testProp2''')
-  additional_properties: Optional[dict[str, Any]] = Field(exclude=True, default=None, alias='''additionalProperties''')
+  test_prop2: Optional[str] = Field(default=None)
+  additional_properties: Optional[dict[str, Any]] = Field(exclude=True, default=None)
 
   @model_serializer(mode='wrap')
   def custom_serializer(self, handler):
@@ -132,6 +138,8 @@ Array [
   @model_validator(mode='before')
   @classmethod
   def unwrap_additional_properties(cls, data):
+    if not isinstance(data, dict):
+      data = data.model_dump()
     json_properties = list(data.keys())
     known_object_properties = ['test_prop2', 'additional_properties']
     unknown_object_properties = [element for element in json_properties if element not in known_object_properties]
@@ -140,11 +148,11 @@ Array [
       return data
   
     known_json_properties = ['testProp2', 'additionalProperties']
-    additional_properties = {}
+    additional_properties = data.get('additional_properties', {})
     for obj_key in list(data.keys()):
       if not known_json_properties.__contains__(obj_key):
         additional_properties[obj_key] = data.pop(obj_key, None)
-    data['additionalProperties'] = additional_properties
+    data['additional_properties'] = additional_properties
     return data
 
 ",