--- a/make/autoconf/flags-cflags.m4	Sat Mar 03 09:14:01 2018 +0100
+++ b/make/autoconf/flags-cflags.m4	Mon Mar 05 21:37:20 2018 +0100
@@ -194,7 +194,7 @@
       WARNINGS_ENABLE_ALL_CXXFLAGS="+w +w2"
 
       DISABLED_WARNINGS_C="E_OLD_STYLE_FUNC_DECL E_OLD_STYLE_FUNC_DEF E_SEMANTICS_OF_OP_CHG_IN_ANSI_C E_NO_REPLACEMENT_IN_STRING"
-      DISABLED_WARNINGS_CXX="inllargeuse notused wemptydecl wunreachable"
+      DISABLED_WARNINGS_CXX="inllargeuse notused wemptydecl"
       ;;
     gcc)
       # Prior to gcc 4.4, a -Wno-X where X is unknown for that version of gcc will cause an error