diff --git a/src/bdat.c b/src/bdat.c
index b74c5474..85472074 100644
--- a/src/bdat.c
+++ b/src/bdat.c
@@ -87,7 +87,7 @@ void process_bdat(struct smtp_session *session, char *readbuf, int readlen, stru
       close(session->fd);
       unlink(session->ttmpfile);
 
-      session->fd = 1;
+      session->fd = -1;
    }