diff -Nrup a/main.c b/main.c

--- a/main.c	2016-07-05 17:44:14.957064711 -0400

+++ b/main.c	2016-07-05 17:47:26.681702820 -0400

@@ -3147,7 +3147,8 @@ clean_jobserver (int status)

                "INTERNAL: Exiting with %u jobserver tokens (should be 0)!",

                jobserver_tokens);

       else

-        while (jobserver_tokens--)

+        /* Don't write back the "free" token */

+        while (--jobserver_tokens)

           {

             int r;