diff --git a/spectree/_types.py b/spectree/_types.py
index b7579e50..5c36ee4d 100644
--- a/spectree/_types.py
+++ b/spectree/_types.py
@@ -17,6 +17,7 @@
 ModelType = Type[BaseModel]
 OptionalModelType = Optional[ModelType]
 NamingStrategy = Callable[[ModelType], str]
+NestedNamingStrategy = Callable[[str, str], str]
 
 
 class MultiDict(Protocol):
diff --git a/spectree/spec.py b/spectree/spec.py
index aacebf84..66836bbc 100644
--- a/spectree/spec.py
+++ b/spectree/spec.py
@@ -13,7 +13,7 @@
     get_type_hints,
 )
 
-from ._types import FunctionDecorator, ModelType, NamingStrategy
+from ._types import FunctionDecorator, ModelType, NamingStrategy, NestedNamingStrategy
 from .config import Configuration, ModeEnum
 from .models import Tag, ValidationError
 from .plugins import PLUGINS, BasePlugin
@@ -23,6 +23,7 @@
     default_before_handler,
     get_model_key,
     get_model_schema,
+    get_nested_key,
     get_security,
     parse_comments,
     parse_name,
@@ -65,9 +66,11 @@ def __init__(
         validation_error_status: int = 422,
         validation_error_model: Optional[ModelType] = None,
         naming_strategy: NamingStrategy = get_model_key,
+        nested_naming_strategy: NestedNamingStrategy = get_nested_key,
         **kwargs: Any,
     ):
         self.naming_strategy = naming_strategy
+        self.nested_naming_strategy = nested_naming_strategy
         self.before = before
         self.after = after
         self.validation_error_status = validation_error_status
@@ -261,7 +264,11 @@ def _add_model(self, model: ModelType) -> str:
 
         model_key = self.naming_strategy(model)
         self.models[model_key] = deepcopy(
-            get_model_schema(model=model, naming_strategy=self.naming_strategy)
+            get_model_schema(
+                model=model,
+                naming_strategy=self.naming_strategy,
+                nested_naming_strategy=self.nested_naming_strategy,
+            )
         )
 
         return model_key
@@ -350,7 +357,9 @@ def _get_model_definitions(self) -> Dict[str, Any]:
         for name, schema in self.models.items():
             if "definitions" in schema:
                 for key, value in schema["definitions"].items():
-                    definitions[f"{name}.{key}"] = value
+                    composed_key = self.nested_naming_strategy(name, key)
+                    if composed_key not in definitions:
+                        definitions[composed_key] = value
                 del schema["definitions"]
 
         return definitions
diff --git a/spectree/utils.py b/spectree/utils.py
index 615a1a8e..52af7c74 100644
--- a/spectree/utils.py
+++ b/spectree/utils.py
@@ -18,7 +18,7 @@
 
 from pydantic import BaseModel, ValidationError
 
-from ._types import ModelType, MultiDict, NamingStrategy
+from ._types import ModelType, MultiDict, NamingStrategy, NestedNamingStrategy
 
 # parse HTTP status code to get the code
 HTTP_CODE = re.compile(r"^HTTP_(?P<code>\d{3})$")
@@ -229,7 +229,22 @@ def get_model_key(model: ModelType) -> str:
     return f"{model.__name__}.{hash_module_path(module_path=model.__module__)}"
 
 
-def get_model_schema(model: ModelType, naming_strategy: NamingStrategy = get_model_key):
+def get_nested_key(parent: str, child: str) -> str:
+    """
+    generate nested model reference name suffixed by parent model name
+
+    :param parent: string of parent name
+    :param child: string of child name
+    """
+
+    return f"{parent}.{child}"
+
+
+def get_model_schema(
+    model: ModelType,
+    naming_strategy: NamingStrategy = get_model_key,
+    nested_naming_strategy: NestedNamingStrategy = get_nested_key,
+):
     """
     return a dictionary representing the model as JSON Schema with a hashed
     infix in ref to ensure name uniqueness
@@ -239,9 +254,9 @@ def get_model_schema(model: ModelType, naming_strategy: NamingStrategy = get_mod
     """
     assert issubclass(model, BaseModel)
 
-    return model.schema(
-        ref_template=f"#/components/schemas/{naming_strategy(model)}.{{model}}"
-    )
+    nested_key = nested_naming_strategy(naming_strategy(model), "{model}")
+
+    return model.schema(ref_template=f"#/components/schemas/{nested_key}")
 
 
 def get_security(security: Union[None, Mapping, Sequence[Any]]) -> List[Any]: