diff --git a/src/sghi/etl/commons/processors.py b/src/sghi/etl/commons/processors.py
index 58650a6..98add64 100644
--- a/src/sghi/etl/commons/processors.py
+++ b/src/sghi/etl/commons/processors.py
@@ -161,6 +161,7 @@ def dispose(self) -> None:
         self._logger.info("Disposal complete.")
 
 
+@final
 class _ProcessorOfCallable(Processor[_RDT, _PDT], Generic[_RDT, _PDT]):
     __slots__ = ("_delegate_to", "_is_disposed", "_logger")