diff --git a/src/protocol.h b/src/protocol.h
--- a/src/protocol.h
+++ b/src/protocol.h
@@ -1,5 +1,5 @@
 // Copyright (c) 2009-2010 Satoshi Nakamoto
-// Copyright (c) 2009-2016 The Bitcoin Core developers
+// Copyright (c) 2009-2019 The Bitcoin Core developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
@@ -335,9 +335,7 @@
     // advertising this bit, but no longer do as of protocol version 70011 (=
     // NO_BLOOM_VERSION)
     NODE_BLOOM = (1 << 2),
-    // NODE_XTHIN means the node supports Xtreme Thinblocks. If this is turned
-    // off then the node will not service nor make xthin requests.
-    NODE_XTHIN = (1 << 4),
+    // Bit 4 was NODE_XTHIN, removed in v0.22.12
 
     // Bit 5 was NODE_BITCOIN_CASH, removed in v0.22.8
 
diff --git a/src/protocol.cpp b/src/protocol.cpp
--- a/src/protocol.cpp
+++ b/src/protocol.cpp
@@ -273,8 +273,6 @@
             return "GETUTXO";
         case NODE_BLOOM:
             return "BLOOM";
-        case NODE_XTHIN:
-            return "XTHIN";
         case NODE_NETWORK_LIMITED:
             return "NETWORK_LIMITED";
         case NODE_COMPACT_FILTERS:
diff --git a/src/qt/guiutil.cpp b/src/qt/guiutil.cpp
--- a/src/qt/guiutil.cpp
+++ b/src/qt/guiutil.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2011-2016 The Bitcoin Core developers
+// Copyright (c) 2011-2019 The Bitcoin Core developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
diff --git a/src/seeder/main.cpp b/src/seeder/main.cpp
--- a/src/seeder/main.cpp
+++ b/src/seeder/main.cpp
@@ -115,8 +115,6 @@
         if (filter_whitelist.empty()) {
             filter_whitelist.insert(NODE_NETWORK);
             filter_whitelist.insert(NODE_NETWORK | NODE_BLOOM);
-            filter_whitelist.insert(NODE_NETWORK | NODE_XTHIN);
-            filter_whitelist.insert(NODE_NETWORK | NODE_BLOOM | NODE_XTHIN);
         }
         return CONTINUE_EXECUTION;
     }
diff --git a/test/functional/test_framework/messages.py b/test/functional/test_framework/messages.py
--- a/test/functional/test_framework/messages.py
+++ b/test/functional/test_framework/messages.py
@@ -50,7 +50,7 @@
 NODE_GETUTXO = (1 << 1)
 NODE_BLOOM = (1 << 2)
 # NODE_WITNESS = (1 << 3)
-NODE_XTHIN = (1 << 4)
+# NODE_XTHIN = (1 << 4) # removed in v0.22.12
 NODE_COMPACT_FILTERS = (1 << 6)
 NODE_NETWORK_LIMITED = (1 << 10)
 NODE_AVALANCHE = (1 << 24)