diff --git a/test/sanitizer_suppressions/ubsan b/test/sanitizer_suppressions/ubsan
index ca7f9b2804..817b9c5082 100644
--- a/test/sanitizer_suppressions/ubsan
+++ b/test/sanitizer_suppressions/ubsan
@@ -79,6 +79,7 @@ implicit-unsigned-integer-truncation:leveldb/*
 implicit-integer-sign-change:crc32c/*
 
 implicit-signed-integer-truncation:script/interpreter.cpp
+implicit-integer-sign-change:blech32.cpp
 implicit-integer-sign-change:primitives/block.h
 implicit-integer-sign-change:primitives/confidential.cpp
 implicit-integer-sign-change:primitives/confidential.h