--- a/src/include/utils/memdebug.h
+++ b/src/include/utils/memdebug.h
@@ -39,7 +39,7 @@ static inline void
  wipe_mem(void *ptr, size_t size)
  {
     VALGRIND_MAKE_MEM_UNDEFINED(ptr, size);
-   memset(ptr, 0x7F, size);
+   memset(ptr, 0, size);
     VALGRIND_MAKE_MEM_NOACCESS(ptr, size);
  }