diff --git a/sim_console.c b/sim_console.c
index d8cef948..11f55c23 100644
--- a/sim_console.c
+++ b/sim_console.c
@@ -1860,6 +1860,7 @@ else {
         *pref = NULL;
         return SCPE_OPENERR;
         }
+    setvbuf (*pf, NULL, _IOFBF, 65536);
     (*pref)->file = *pf;
     (*pref)->refcount = 1;                               /* need close */
     }
diff --git a/sim_tmxr.c b/sim_tmxr.c
index 6bf0ef1f..7dec384a 100644
--- a/sim_tmxr.c
+++ b/sim_tmxr.c
@@ -2598,9 +2598,7 @@ while (*tptr) {
                 else
                     strcpy (lp->txlogname, mp->logfiletmpl);
                 r = sim_open_logfile (lp->txlogname, TRUE, &lp->txlog, &lp->txlogref);
-                if (r == SCPE_OK)
-                    setvbuf (lp->txlog, NULL, _IOFBF, 65536);
-                else {
+                if (r != SCPE_OK) {
                     free (lp->txlogname);
                     lp->txlogname = NULL;
                     break;