diff --git a/src/terminal.c b/src/terminal.c
index 86b8647..1d81d8d 100644
--- a/src/terminal.c
+++ b/src/terminal.c
@@ -3192,7 +3192,7 @@
 	    p = get_dict_string(dict, (char_u *)"encoding", FALSE);
 	if (p != NULL)
 	{
-	    ea.cmd = alloc((int)STRLEN(p) + 10);
+	    ea.cmd = alloc((int)STRLEN(p) + 12);
 	    if (ea.cmd != NULL)
 	    {
 		sprintf((char *)ea.cmd, "sbuf ++enc=%s", p);