diff --git a/Game/Levels/Algorithm/L06is_zero.lean b/Game/Levels/Algorithm/L06is_zero.lean
index 9d1ce8f..7f6f5f8 100644
--- a/Game/Levels/Algorithm/L06is_zero.lean
+++ b/Game/Levels/Algorithm/L06is_zero.lean
@@ -61,3 +61,5 @@ Statement succ_ne_zero (a : ℕ) : succ a ≠ 0 := by
   rw [h]
   rw [is_zero_zero]
   triv
+
+DisabledTheorem MyNat.zero_ne_succ