diff --git a/src/include/pg_config_manual.h b/src/include/pg_config_manual.h
index f2a106f983d..66ab343d51c 100644
--- a/src/include/pg_config_manual.h
+++ b/src/include/pg_config_manual.h
@@ -82,9 +82,7 @@
  *
  * Changing this requires an initdb.
  */
-#if SIZEOF_VOID_P >= 8
-#define USE_FLOAT8_BYVAL 1
-#endif
+#undef USE_FLOAT8_BYVAL
 
 /*
  * When we don't have native spinlocks, we use semaphores to simulate them.
diff --git a/src/include/utils/memdebug.h b/src/include/utils/memdebug.h
index 6876e0aceff..7accee958d0 100644
--- 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);
 }