diff --git a/lib/replace/wscript b/lib/replace/wscript
index 66694f7d0af..fd00a42d5b6 100644
--- a/lib/replace/wscript
+++ b/lib/replace/wscript
@@ -293,7 +293,7 @@ def configure(conf):
                     ''',
                     'HAVE_FALLTHROUGH_ATTRIBUTE',
                     addmain=False,
-                    cflags='-Werror',
+                    strict=True,
                     msg='Checking for fallthrough attribute')
 
     # these may be builtins, so we need the link=False strategy