# MutantHub mutant #4021: Constant replacement mutation at validation.cpp:2152
# Repository: bitcoin/bitcoin @ ddea9196493d3b8fd841a36a6c53efd85dac7a05
# File: src/validation.cpp:2152-2152
# Review: APPROVED; outcome: SURVIVED
--- a/src/validation.cpp
+++ b/src/validation.cpp
@@ -2152,1 +2152,1 @@
-            undo.nHeight = alternate.nHeight;
+            undo.nHeight = true;