diff --git a/m4/attributes.m4 b/m4/attributes.m4
index db5df250f4..51ac88be61 100644
--- a/m4/attributes.m4
+++ b/m4/attributes.m4
@@ -43,7 +43,7 @@ AC_DEFUN([CC_CHECK_FLAG_APPEND], [
   AC_CACHE_CHECK([if $CC supports flag $3 in envvar $2],
                  AS_TR_SH([cc_cv_$2_$3]),
           [eval "AS_TR_SH([cc_save_$2])='${$2}'"
-           eval "AS_TR_SH([$2])='-Werror `echo "$3" | sed 's/^-Wno-/-W/'`'"
+           eval "AS_TR_SH([$2])='${cc_save_$2} -Werror `echo "$3" | sed 's/^-Wno-/-W/'`'"
            AC_LINK_IFELSE([AC_LANG_SOURCE(ifelse([$4], [],
                                                  [int main(void) { return 0; } ],
                                                  [$4]))],