--- lib/replace/wscript.orig	2019-03-21 10:12:32 UTC
+++ lib/replace/wscript
@@ -119,7 +119,7 @@ def configure(conf):
     conf.CHECK_HEADERS('sys/atomic.h stdatomic.h')
     conf.CHECK_HEADERS('libgen.h')
 
-    if conf.CHECK_CFLAGS('-Wno-format-truncation'):
+    if conf.CHECK_CFLAGS(['-Wno-format-truncation'] + conf.env.WERROR_CFLAGS):
         conf.define('HAVE_WNO_FORMAT_TRUNCATION', '1')
 
     if conf.CHECK_CFLAGS('-Wno-unused-function'):