diff --git a/fastapi/_compat/__init__.py b/fastapi/_compat/__init__.py
index b7701bd1a..22bc28dec 100644
--- a/fastapi/_compat/__init__.py
+++ b/fastapi/_compat/__init__.py
@@ -25,7 +25,6 @@ from .v2 import copy_field_info as copy_field_info
 from .v2 import create_body_model as create_body_model
 from .v2 import evaluate_forwardref as evaluate_forwardref
 from .v2 import get_cached_model_fields as get_cached_model_fields
-from .v2 import get_compat_model_name_map as get_compat_model_name_map
 from .v2 import get_definitions as get_definitions
 from .v2 import get_missing_field_error as get_missing_field_error
 from .v2 import get_schema_from_model_field as get_schema_from_model_field
diff --git a/fastapi/_compat/v2.py b/fastapi/_compat/v2.py
index 6c2eec58b..1b98b74e5 100644
--- a/fastapi/_compat/v2.py
+++ b/fastapi/_compat/v2.py
@@ -499,11 +499,6 @@ def get_model_name_map(unique_models: TypeModelSet) -> dict[TypeModelOrEnum, str
     return {v: k for k, v in name_model_map.items()}
 
 
-def get_compat_model_name_map(fields: list[ModelField]) -> ModelNameMap:
-    flat_models = get_flat_models_from_fields(fields, known_models=set())
-    return get_model_name_map(flat_models)
-
-
 def get_flat_models_from_model(
     model: type["BaseModel"], known_models: Union[TypeModelSet, None] = None
 ) -> TypeModelSet:
diff --git a/fastapi/openapi/utils.py b/fastapi/openapi/utils.py
index 5736af3b7..c9b006a71 100644
--- a/fastapi/openapi/utils.py
+++ b/fastapi/openapi/utils.py
@@ -9,11 +9,14 @@ from fastapi import routing
 from fastapi._compat import (
     ModelField,
     Undefined,
-    get_compat_model_name_map,
     get_definitions,
     get_schema_from_model_field,
     lenient_issubclass,
 )
+from fastapi._compat.v2 import (
+    get_flat_models_from_fields,
+    get_model_name_map,
+)
 from fastapi.datastructures import DefaultPlaceholder
 from fastapi.dependencies.models import Dependant
 from fastapi.dependencies.utils import (
@@ -512,7 +515,8 @@ def get_openapi(
     webhook_paths: dict[str, dict[str, Any]] = {}
     operation_ids: set[str] = set()
     all_fields = get_fields_from_routes(list(routes or []) + list(webhooks or []))
-    model_name_map = get_compat_model_name_map(all_fields)
+    flat_models = get_flat_models_from_fields(all_fields, known_models=set())
+    model_name_map = get_model_name_map(flat_models)
     field_mapping, definitions = get_definitions(
         fields=all_fields,
         model_name_map=model_name_map,