diff --git a/src/session.c b/src/session.c
index d0373bb..a734656 100644
--- a/src/session.c
+++ b/src/session.c
@@ -402,7 +402,8 @@
 	buf_T *alt = buflist_findnr(wp->w_alt_fnum);
 
 	// Set the alternate file.
-	if (alt != NULL
+	if ((flagp == &ssop_flags)
+		&& alt != NULL
 		&& alt->b_fname != NULL
 		&& *alt->b_fname != NUL
 		&& (fputs("balt ", fd) < 0