diff -rupN libQtShadowsocks-2.1.0/lib/crypto/cipher.cpp libQtShadowsocks-2.1.0.new/lib/crypto/cipher.cpp
--- libQtShadowsocks-2.1.0/lib/crypto/cipher.cpp	2018-04-21 06:51:05.000000000 +0800
+++ libQtShadowsocks-2.1.0.new/lib/crypto/cipher.cpp	2021-04-15 12:47:17.568896619 +0800
@@ -26,6 +26,7 @@
 #include <stdexcept>
 
 #include <botan/auto_rng.h>
+#include <botan/filters.h>
 #include <botan/key_filt.h>
 #include <botan/lookup.h>
 #include <botan/md5.h>
