diff --git a/src/lighteval/tasks/tasks/truthfulqa.py b/src/lighteval/tasks/tasks/truthfulqa.py
index f517f049e..d88841be3 100644
--- a/src/lighteval/tasks/tasks/truthfulqa.py
+++ b/src/lighteval/tasks/tasks/truthfulqa.py
@@ -51,7 +51,6 @@ def truthful_qa_generative_prompt(line, task_name: str = None):
         query=line["question"].strip(),
         choices=correct_answers + incorrect_answers,
         gold_index=list(range(len(correct_answers))),
-        specific={"len_mc1": len(line["mc1_targets"]["choices"])},
     )