diff --git a/src/smolagents/agents.py b/src/smolagents/agents.py
index 468da08c8..626a1c36c 100644
--- a/src/smolagents/agents.py
+++ b/src/smolagents/agents.py
@@ -510,7 +510,7 @@ def _execute_step(self, memory_step: ActionStep) -> Generator[ChatMessageStreamD
                 yield el
             elif isinstance(el, FinalOutput):
                 final_answer = el.output
-                if self.final_answer_checks:
+                if self.final_answer_checks and final_answer is not None:
                     self._validate_final_answer(final_answer)
                 yield final_answer