diff --git a/src/proxy.c b/src/proxy.c
index a88321b..854db6c 100644
--- a/src/proxy.c
+++ b/src/proxy.c
@@ -1585,7 +1585,7 @@
 	es->buf_len = buf_len;
 	es->ev_id   = ev_id;
 
-	len1 = b_size(buf) - buf_len;
+	len1 = b_size(buf) - b_peek_ofs(buf, buf_out);
 	if (len1 > buf_len)
 		len1 = buf_len;