diff --git a/fastapi/routing.py b/fastapi/routing.py
index a8e12eb60..6929a0661 100644
--- a/fastapi/routing.py
+++ b/fastapi/routing.py
@@ -308,7 +308,7 @@ def get_request_handler(
     embed_body_fields: bool = False,
 ) -> Callable[[Request], Coroutine[Any, Any, Response]]:
     assert dependant.call is not None, "dependant.call must be a function"
-    is_coroutine = iscoroutinefunction(dependant.call)
+    is_coroutine = dependant.is_coroutine_callable
     is_body_form = body_field and isinstance(
         body_field.field_info, (params.Form, temp_pydantic_v1_params.Form)
     )