--- a/common/autoconf/flags.m4	Thu Nov 05 15:14:39 2015 +0100
+++ b/common/autoconf/flags.m4	Thu Nov 05 17:32:57 2015 +0100
@@ -942,7 +942,16 @@
   else
     AC_MSG_ERROR([--enable-warnings-as-errors accepts no argument])
   fi
+
+  if test "x$WARNINGS_AS_ERRORS" = "xfalse"; then
+    # Set legacy hotspot variable
+    HOTSPOT_SET_WARNINGS_AS_ERRORS=WARNINGS_ARE_ERRORS=
+  else
+    HOTSPOT_SET_WARNINGS_AS_ERRORS=
+  fi
+
   AC_SUBST(WARNINGS_AS_ERRORS)
+  AC_SUBST(HOTSPOT_SET_WARNINGS_AS_ERRORS)
 
   case "${TOOLCHAIN_TYPE}" in
     microsoft)