diff --git a/configure.ac b/configure.ac
index b03b7a5..62faf98 100644
--- a/configure.ac
+++ b/configure.ac
@@ -157,6 +157,7 @@
     # Use runtime(json) config, otherwise default to compile time(yaml) config
     AM_COND_IF([WANT_JSON_CONTROL],
     [
+        AC_ARG_VAR(MACHINE, [Machine name to install a particular set of associated config file(s)])
         AC_CHECK_HEADER(nlohmann/json.hpp, ,
                 [AC_MSG_ERROR([Could not find nlohmann/json.hpp... nlohmann/json package required])])
         # Set config flag for runtime json usage