diff --git a/src/thue_morse3.v b/src/thue_morse3.v
index 9475711..9e681de 100644
--- a/src/thue_morse3.v
+++ b/src/thue_morse3.v
@@ -2096,7 +2096,7 @@ Proof.
 Qed.
 
 
-Lemma tm_step_non_proper_palindrome_16 :
+Lemma tm_step_palindrome_8_destruct :
   forall (n : nat) (hd a tl : list bool),
   tm_step n = hd ++ a ++ (rev a) ++ tl
   -> length a = 8