diff --git a/src/bench/checkblock.cpp b/src/bench/checkblock.cpp
index 9f52a226725..b81878006cd 100644
--- a/src/bench/checkblock.cpp
+++ b/src/bench/checkblock.cpp
@@ -18,7 +18,7 @@
 
 static void DeserializeBlockTest(benchmark::Bench& bench)
 {
-    CDataStream stream(benchmark::data::block413567, SER_NETWORK, PROTOCOL_VERSION);
+    DataStream stream(benchmark::data::block413567);
     std::byte a{0};
     stream.write({&a, 1}); // Prevent compaction
 
@@ -32,7 +32,7 @@ static void DeserializeBlockTest(benchmark::Bench& bench)
 
 static void DeserializeAndCheckBlockTest(benchmark::Bench& bench)
 {
-    CDataStream stream(benchmark::data::block413567, SER_NETWORK, PROTOCOL_VERSION);
+    DataStream stream(benchmark::data::block413567);
     std::byte a{0};
     stream.write({&a, 1}); // Prevent compaction
 
diff --git a/src/bench/verify_script.cpp b/src/bench/verify_script.cpp
index e1a0bf138eb..3682b335187 100644
--- a/src/bench/verify_script.cpp
+++ b/src/bench/verify_script.cpp
@@ -61,7 +61,7 @@ static void VerifyScriptBench(benchmark::Bench& bench)
         assert(success);
 
 #if defined(HAVE_CONSENSUS_LIB)
-        CDataStream stream(SER_NETWORK, PROTOCOL_VERSION);
+        DataStream stream;
         stream << TX_WITH_WITNESS(txSpend);
         int csuccess = bitcoinconsensus_verify_script_with_amount(
             txCredit.vout[0].scriptPubKey.data(),
diff --git a/src/bitcoin-util.cpp b/src/bitcoin-util.cpp
index 8b68d04b2bf..96387e8c71e 100644
--- a/src/bitcoin-util.cpp
+++ b/src/bitcoin-util.cpp
@@ -19,7 +19,6 @@
 #include <util/exception.h>
 #include <util/strencodings.h>
 #include <util/translation.h>
-#include <version.h>
 
 #include <atomic>
 #include <cstdio>
diff --git a/src/blockencodings.cpp b/src/blockencodings.cpp
index 29306b22290..1e940e8f03e 100644
--- a/src/blockencodings.cpp
+++ b/src/blockencodings.cpp
@@ -164,7 +164,7 @@ ReadStatus PartiallyDownloadedBlock::InitData(const CBlockHeaderAndShortTxIDs& c
             break;
     }
 
-    LogPrint(BCLog::CMPCTBLOCK, "Initialized PartiallyDownloadedBlock for block %s using a cmpctblock of size %lu\n", cmpctblock.header.GetHash().ToString(), GetSerializeSize(cmpctblock, PROTOCOL_VERSION));
+    LogPrint(BCLog::CMPCTBLOCK, "Initialized PartiallyDownloadedBlock for block %s using a cmpctblock of size %lu\n", cmpctblock.header.GetHash().ToString(), GetSerializeSize(cmpctblock));
 
     return READ_STATUS_OK;
 }
diff --git a/src/coins.cpp b/src/coins.cpp
index b44d920ee1f..f576fae7488 100644
--- a/src/coins.cpp
+++ b/src/coins.cpp
@@ -8,7 +8,6 @@
 #include <logging.h>
 #include <random.h>
 #include <util/trace.h>
-#include <version.h>
 
 bool CCoinsView::GetCoin(const COutPoint &outpoint, Coin &coin) const { return false; }
 uint256 CCoinsView::GetBestBlock() const { return uint256(); }
@@ -339,7 +338,7 @@ void CCoinsViewCache::SanityCheck() const
     assert(recomputed_usage == cachedCoinsUsage);
 }
 
-static const size_t MIN_TRANSACTION_OUTPUT_WEIGHT = WITNESS_SCALE_FACTOR * ::GetSerializeSize(CTxOut(), PROTOCOL_VERSION);
+static const size_t MIN_TRANSACTION_OUTPUT_WEIGHT = WITNESS_SCALE_FACTOR * ::GetSerializeSize(CTxOut());
 static const size_t MAX_OUTPUTS_PER_BLOCK = MAX_BLOCK_WEIGHT / MIN_TRANSACTION_OUTPUT_WEIGHT;
 
 const Coin& AccessByTxid(const CCoinsViewCache& view, const uint256& txid)
diff --git a/src/consensus/validation.h b/src/consensus/validation.h
index 3fdc01e66b9..1556c7888f9 100644
--- a/src/consensus/validation.h
+++ b/src/consensus/validation.h
@@ -7,7 +7,6 @@
 #define BITCOIN_CONSENSUS_VALIDATION_H
 
 #include <string>
-#include <version.h>
 #include <consensus/consensus.h>
 #include <primitives/transaction.h>
 #include <primitives/block.h>
diff --git a/src/core_read.cpp b/src/core_read.cpp
index bffb9e90425..e32e46d1b9b 100644
--- a/src/core_read.cpp
+++ b/src/core_read.cpp
@@ -12,7 +12,6 @@
 #include <streams.h>
 #include <util/result.h>
 #include <util/strencodings.h>
-#include <version.h>
 
 #include <algorithm>
 #include <string>
diff --git a/src/external_signer.cpp b/src/external_signer.cpp
index 102c58b56aa..15024f6e0f2 100644
--- a/src/external_signer.cpp
+++ b/src/external_signer.cpp
@@ -2,12 +2,14 @@
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
+#include <external_signer.h>
+
 #include <chainparams.h>
 #include <common/run_command.h>
 #include <core_io.h>
 #include <psbt.h>
 #include <util/strencodings.h>
-#include <external_signer.h>
+#include <version.h>
 
 #include <algorithm>
 #include <stdexcept>
diff --git a/src/hash.h b/src/hash.h
index 132e1a9fb39..52babf8b1d9 100644
--- a/src/hash.h
+++ b/src/hash.h
@@ -14,7 +14,6 @@
 #include <serialize.h>
 #include <span.h>
 #include <uint256.h>
-#include <version.h>
 
 #include <string>
 #include <vector>
diff --git a/src/index/blockfilterindex.cpp b/src/index/blockfilterindex.cpp
index 5fda798efd6..58f777b3266 100644
--- a/src/index/blockfilterindex.cpp
+++ b/src/index/blockfilterindex.cpp
@@ -174,8 +174,8 @@ size_t BlockFilterIndex::WriteFilterToDisk(FlatFilePos& pos, const BlockFilter&
     assert(filter.GetFilterType() == GetFilterType());
 
     size_t data_size =
-        GetSerializeSize(filter.GetBlockHash(), CLIENT_VERSION) +
-        GetSerializeSize(filter.GetEncodedFilter(), CLIENT_VERSION);
+        GetSerializeSize(filter.GetBlockHash()) +
+        GetSerializeSize(filter.GetEncodedFilter());
 
     // If writing the filter would overflow the file, flush and move to the next one.
     if (pos.nPos + data_size > MAX_FLTR_FILE_SIZE) {
diff --git a/src/kernel/coinstats.cpp b/src/kernel/coinstats.cpp
index 9bd755ed271..302638cdbea 100644
--- a/src/kernel/coinstats.cpp
+++ b/src/kernel/coinstats.cpp
@@ -21,7 +21,6 @@
 #include <util/check.h>
 #include <util/overflow.h>
 #include <validation.h>
-#include <version.h>
 
 #include <cassert>
 #include <iosfwd>
diff --git a/src/net.h b/src/net.h
index 16312cf72d4..aa75df075d7 100644
--- a/src/net.h
+++ b/src/net.h
@@ -30,6 +30,7 @@
 #include <util/check.h>
 #include <util/sock.h>
 #include <util/threadinterrupt.h>
+#include <version.h>
 
 #include <atomic>
 #include <condition_variable>
diff --git a/src/node/blockstorage.cpp b/src/node/blockstorage.cpp
index 1108cc676b6..c066d1c939f 100644
--- a/src/node/blockstorage.cpp
+++ b/src/node/blockstorage.cpp
@@ -662,7 +662,7 @@ bool BlockManager::UndoWriteToDisk(const CBlockUndo& blockundo, FlatFilePos& pos
     }
 
     // Write index header
-    unsigned int nSize = GetSerializeSize(blockundo, CLIENT_VERSION);
+    unsigned int nSize = GetSerializeSize(blockundo);
     fileout << GetParams().MessageStart() << nSize;
 
     // Write undo data
@@ -979,7 +979,7 @@ bool BlockManager::WriteUndoDataForBlock(const CBlockUndo& blockundo, BlockValid
     // Write undo information to disk
     if (block.GetUndoPos().IsNull()) {
         FlatFilePos _pos;
-        if (!FindUndoPos(state, block.nFile, _pos, ::GetSerializeSize(blockundo, CLIENT_VERSION) + 40)) {
+        if (!FindUndoPos(state, block.nFile, _pos, ::GetSerializeSize(blockundo) + 40)) {
             return error("ConnectBlock(): FindUndoPos failed");
         }
         if (!UndoWriteToDisk(blockundo, _pos, block.pprev->GetBlockHash())) {
diff --git a/src/primitives/transaction.cpp b/src/primitives/transaction.cpp
index 6650277c2b6..82fb59d3494 100644
--- a/src/primitives/transaction.cpp
+++ b/src/primitives/transaction.cpp
@@ -13,7 +13,6 @@
 #include <uint256.h>
 #include <util/strencodings.h>
 #include <util/transaction_identifier.h>
-#include <version.h>
 
 #include <cassert>
 #include <stdexcept>
diff --git a/src/psbt.cpp b/src/psbt.cpp
index 76a2fd82417..e46032f5d50 100644
--- a/src/psbt.cpp
+++ b/src/psbt.cpp
@@ -8,6 +8,7 @@
 #include <script/signingprovider.h>
 #include <util/check.h>
 #include <util/strencodings.h>
+#include <version.h>
 
 
 PartiallySignedTransaction::PartiallySignedTransaction(const CMutableTransaction& tx) : tx(tx)
diff --git a/src/psbt.h b/src/psbt.h
index 1fd186f6a56..a14df038378 100644
--- a/src/psbt.h
+++ b/src/psbt.h
@@ -89,7 +89,9 @@ struct PSBTProprietary
 template<typename Stream, typename... X>
 void SerializeToVector(Stream& s, const X&... args)
 {
-    WriteCompactSize(s, GetSerializeSizeMany(s.GetVersion(), args...));
+    SizeComputer sizecomp;
+    SerializeMany(sizecomp, args...);
+    WriteCompactSize(s, sizecomp.size());
     SerializeMany(s, args...);
 }
 
diff --git a/src/rest.cpp b/src/rest.cpp
index f86c47ee6be..3894b5141d5 100644
--- a/src/rest.cpp
+++ b/src/rest.cpp
@@ -28,7 +28,6 @@
 #include <util/check.h>
 #include <util/strencodings.h>
 #include <validation.h>
-#include <version.h>
 
 #include <any>
 #include <string>
diff --git a/src/rpc/blockchain.cpp b/src/rpc/blockchain.cpp
index 9a29b73bee0..6a3aa397d91 100644
--- a/src/rpc/blockchain.cpp
+++ b/src/rpc/blockchain.cpp
@@ -1861,7 +1861,7 @@ static RPCHelpMan getblockstats()
             for (const CTxOut& out : tx->vout) {
                 tx_total_out += out.nValue;
 
-                size_t out_size = GetSerializeSize(out, PROTOCOL_VERSION) + PER_UTXO_OVERHEAD;
+                size_t out_size = GetSerializeSize(out) + PER_UTXO_OVERHEAD;
                 utxo_size_inc += out_size;
 
                 // The Genesis block and the repeated BIP30 block coinbases don't change the UTXO
@@ -1913,7 +1913,7 @@ static RPCHelpMan getblockstats()
                 const CTxOut& prevoutput = coin.out;
 
                 tx_total_in += prevoutput.nValue;
-                size_t prevout_size = GetSerializeSize(prevoutput, PROTOCOL_VERSION) + PER_UTXO_OVERHEAD;
+                size_t prevout_size = GetSerializeSize(prevoutput) + PER_UTXO_OVERHEAD;
                 utxo_size_inc -= prevout_size;
                 utxo_size_inc_actual -= prevout_size;
             }
diff --git a/src/rpc/rawtransaction.cpp b/src/rpc/rawtransaction.cpp
index 397ece08c0d..e8bcbd8a2b1 100644
--- a/src/rpc/rawtransaction.cpp
+++ b/src/rpc/rawtransaction.cpp
@@ -40,6 +40,7 @@
 #include <util/vector.h>
 #include <validation.h>
 #include <validationinterface.h>
+#include <version.h>
 
 #include <numeric>
 #include <stdint.h>
diff --git a/src/script/bitcoinconsensus.cpp b/src/script/bitcoinconsensus.cpp
index 2ca8dac48c1..c4eccacf41b 100644
--- a/src/script/bitcoinconsensus.cpp
+++ b/src/script/bitcoinconsensus.cpp
@@ -8,7 +8,6 @@
 #include <primitives/transaction.h>
 #include <pubkey.h>
 #include <script/interpreter.h>
-#include <version.h>
 
 namespace {
 
diff --git a/src/script/interpreter.cpp b/src/script/interpreter.cpp
index 5f4a1aceb2c..c969ce45f12 100644
--- a/src/script/interpreter.cpp
+++ b/src/script/interpreter.cpp
@@ -1934,7 +1934,7 @@ static bool VerifyWitnessProgram(const CScriptWitness& witness, int witversion,
             if ((control[0] & TAPROOT_LEAF_MASK) == TAPROOT_LEAF_TAPSCRIPT) {
                 // Tapscript (leaf version 0xc0)
                 exec_script = CScript(script.begin(), script.end());
-                execdata.m_validation_weight_left = ::GetSerializeSize(witness.stack, PROTOCOL_VERSION) + VALIDATION_WEIGHT_OFFSET;
+                execdata.m_validation_weight_left = ::GetSerializeSize(witness.stack) + VALIDATION_WEIGHT_OFFSET;
                 execdata.m_validation_weight_left_init = true;
                 return ExecuteWitnessScript(stack, exec_script, flags, SigVersion::TAPSCRIPT, checker, execdata, serror);
             }
diff --git a/src/script/sign.cpp b/src/script/sign.cpp
index 251a8420f74..be4b3575681 100644
--- a/src/script/sign.cpp
+++ b/src/script/sign.cpp
@@ -379,7 +379,7 @@ static bool SignTaproot(const SigningProvider& provider, const BaseSignatureCrea
             result_stack.emplace_back(std::begin(script), std::end(script)); // Push the script
             result_stack.push_back(*control_blocks.begin()); // Push the smallest control block
             if (smallest_result_stack.size() == 0 ||
-                GetSerializeSize(result_stack, PROTOCOL_VERSION) < GetSerializeSize(smallest_result_stack, PROTOCOL_VERSION)) {
+                GetSerializeSize(result_stack) < GetSerializeSize(smallest_result_stack)) {
                 smallest_result_stack = std::move(result_stack);
             }
         }
diff --git a/src/serialize.h b/src/serialize.h
index b09d6fbe608..83715866f56 100644
--- a/src/serialize.h
+++ b/src/serialize.h
@@ -124,7 +124,7 @@ template<typename Stream> inline uint64_t ser_readdata64(Stream &s)
 // i.e. anything that supports .read(Span<std::byte>) and .write(Span<const std::byte>)
 //
 
-class CSizeComputer;
+class SizeComputer;
 
 enum
 {
@@ -324,7 +324,7 @@ constexpr inline unsigned int GetSizeOfCompactSize(uint64_t nSize)
     else                         return sizeof(unsigned char) + sizeof(uint64_t);
 }
 
-inline void WriteCompactSize(CSizeComputer& os, uint64_t nSize);
+inline void WriteCompactSize(SizeComputer& os, uint64_t nSize);
 
 template<typename Stream>
 void WriteCompactSize(Stream& os, uint64_t nSize)
@@ -450,7 +450,7 @@ inline unsigned int GetSizeOfVarInt(I n)
 }
 
 template<typename I>
-inline void WriteVarInt(CSizeComputer& os, I n);
+inline void WriteVarInt(SizeComputer& os, I n);
 
 template<typename Stream, VarIntMode Mode, typename I>
 void WriteVarInt(Stream& os, I n)
@@ -1070,22 +1070,21 @@ struct ActionUnserialize {
 /* ::GetSerializeSize implementations
  *
  * Computing the serialized size of objects is done through a special stream
- * object of type CSizeComputer, which only records the number of bytes written
+ * object of type SizeComputer, which only records the number of bytes written
  * to it.
  *
  * If your Serialize or SerializationOp method has non-trivial overhead for
  * serialization, it may be worthwhile to implement a specialized version for
- * CSizeComputer, which uses the s.seek() method to record bytes that would
+ * SizeComputer, which uses the s.seek() method to record bytes that would
  * be written instead.
  */
-class CSizeComputer
+class SizeComputer
 {
 protected:
     size_t nSize{0};
 
-    const int nVersion;
 public:
-    explicit CSizeComputer(int nVersionIn) : nVersion(nVersionIn) {}
+    SizeComputer() {}
 
     void write(Span<const std::byte> src)
     {
@@ -1099,7 +1098,7 @@ public:
     }
 
     template<typename T>
-    CSizeComputer& operator<<(const T& obj)
+    SizeComputer& operator<<(const T& obj)
     {
         ::Serialize(*this, obj);
         return (*this);
@@ -1108,33 +1107,23 @@ public:
     size_t size() const {
         return nSize;
     }
-
-    int GetVersion() const { return nVersion; }
 };
 
 template<typename I>
-inline void WriteVarInt(CSizeComputer &s, I n)
+inline void WriteVarInt(SizeComputer &s, I n)
 {
     s.seek(GetSizeOfVarInt<I>(n));
 }
 
-inline void WriteCompactSize(CSizeComputer &s, uint64_t nSize)
+inline void WriteCompactSize(SizeComputer &s, uint64_t nSize)
 {
     s.seek(GetSizeOfCompactSize(nSize));
 }
 
 template <typename T>
-size_t GetSerializeSize(const T& t, int nVersion = 0)
+size_t GetSerializeSize(const T& t)
 {
-    return (CSizeComputer(nVersion) << t).size();
-}
-
-template <typename... T>
-size_t GetSerializeSizeMany(int nVersion, const T&... t)
-{
-    CSizeComputer sc(nVersion);
-    SerializeMany(sc, t...);
-    return sc.size();
+    return (SizeComputer() << t).size();
 }
 
 /** Wrapper that overrides the GetParams() function of a stream (and hides GetVersion/GetType). */
diff --git a/src/signet.cpp b/src/signet.cpp
index ef0faaa5f82..d6a3a44d913 100644
--- a/src/signet.cpp
+++ b/src/signet.cpp
@@ -22,6 +22,7 @@
 #include <streams.h>
 #include <uint256.h>
 #include <util/strencodings.h>
+#include <version.h>
 
 static constexpr uint8_t SIGNET_HEADER[4] = {0xec, 0xc7, 0xda, 0xa2};
 
diff --git a/src/test/flatfile_tests.cpp b/src/test/flatfile_tests.cpp
index 3874b38f613..21a36d9d434 100644
--- a/src/test/flatfile_tests.cpp
+++ b/src/test/flatfile_tests.cpp
@@ -40,7 +40,7 @@ BOOST_AUTO_TEST_CASE(flatfile_open)
                       "lost if a trusted third party is still required to prevent double-spending.");
 
     size_t pos1 = 0;
-    size_t pos2 = pos1 + GetSerializeSize(line1, CLIENT_VERSION);
+    size_t pos2 = pos1 + GetSerializeSize(line1);
 
     // Write first line to file.
     {
diff --git a/src/test/fuzz/miniscript.cpp b/src/test/fuzz/miniscript.cpp
index 8c73edfa9dc..0d0ee59ab3f 100644
--- a/src/test/fuzz/miniscript.cpp
+++ b/src/test/fuzz/miniscript.cpp
@@ -1121,7 +1121,7 @@ void TestNode(const MsCtx script_ctx, const NodeRef& node, FuzzedDataProvider& p
         assert(mal_success);
         assert(stack_nonmal == stack_mal);
         // Compute witness size (excluding script push, control block, and witness count encoding).
-        const size_t wit_size = GetSerializeSize(stack_nonmal, PROTOCOL_VERSION) - GetSizeOfCompactSize(stack_nonmal.size());
+        const size_t wit_size = GetSerializeSize(stack_nonmal) - GetSizeOfCompactSize(stack_nonmal.size());
         assert(wit_size <= *node->GetWitnessSize());
 
         // Test non-malleable satisfaction.
diff --git a/src/test/miniscript_tests.cpp b/src/test/miniscript_tests.cpp
index 996c3799629..1f28e61bc91 100644
--- a/src/test/miniscript_tests.cpp
+++ b/src/test/miniscript_tests.cpp
@@ -369,7 +369,7 @@ void TestSatisfy(const KeyConverter& converter, const std::string& testcase, con
             CScriptWitness witness_nonmal;
             const bool nonmal_success = node->Satisfy(satisfier, witness_nonmal.stack, true) == miniscript::Availability::YES;
             // Compute witness size (excluding script push, control block, and witness count encoding).
-            const size_t wit_size = GetSerializeSize(witness_nonmal.stack, PROTOCOL_VERSION) - GetSizeOfCompactSize(witness_nonmal.stack.size());
+            const size_t wit_size = GetSerializeSize(witness_nonmal.stack) - GetSizeOfCompactSize(witness_nonmal.stack.size());
             SatisfactionToWitness(converter.MsContext(), witness_nonmal, script, builder);
 
             if (nonmal_success) {
diff --git a/src/test/serialize_tests.cpp b/src/test/serialize_tests.cpp
index 6d5a14ad9e1..d75eb499b4a 100644
--- a/src/test/serialize_tests.cpp
+++ b/src/test/serialize_tests.cpp
@@ -62,31 +62,31 @@ public:
 
 BOOST_AUTO_TEST_CASE(sizes)
 {
-    BOOST_CHECK_EQUAL(sizeof(unsigned char), GetSerializeSize((unsigned char)0, 0));
-    BOOST_CHECK_EQUAL(sizeof(int8_t), GetSerializeSize(int8_t(0), 0));
-    BOOST_CHECK_EQUAL(sizeof(uint8_t), GetSerializeSize(uint8_t(0), 0));
-    BOOST_CHECK_EQUAL(sizeof(int16_t), GetSerializeSize(int16_t(0), 0));
-    BOOST_CHECK_EQUAL(sizeof(uint16_t), GetSerializeSize(uint16_t(0), 0));
-    BOOST_CHECK_EQUAL(sizeof(int32_t), GetSerializeSize(int32_t(0), 0));
-    BOOST_CHECK_EQUAL(sizeof(uint32_t), GetSerializeSize(uint32_t(0), 0));
-    BOOST_CHECK_EQUAL(sizeof(int64_t), GetSerializeSize(int64_t(0), 0));
-    BOOST_CHECK_EQUAL(sizeof(uint64_t), GetSerializeSize(uint64_t(0), 0));
+    BOOST_CHECK_EQUAL(sizeof(unsigned char), GetSerializeSize((unsigned char)0));
+    BOOST_CHECK_EQUAL(sizeof(int8_t), GetSerializeSize(int8_t(0)));
+    BOOST_CHECK_EQUAL(sizeof(uint8_t), GetSerializeSize(uint8_t(0)));
+    BOOST_CHECK_EQUAL(sizeof(int16_t), GetSerializeSize(int16_t(0)));
+    BOOST_CHECK_EQUAL(sizeof(uint16_t), GetSerializeSize(uint16_t(0)));
+    BOOST_CHECK_EQUAL(sizeof(int32_t), GetSerializeSize(int32_t(0)));
+    BOOST_CHECK_EQUAL(sizeof(uint32_t), GetSerializeSize(uint32_t(0)));
+    BOOST_CHECK_EQUAL(sizeof(int64_t), GetSerializeSize(int64_t(0)));
+    BOOST_CHECK_EQUAL(sizeof(uint64_t), GetSerializeSize(uint64_t(0)));
     // Bool is serialized as uint8_t
-    BOOST_CHECK_EQUAL(sizeof(uint8_t), GetSerializeSize(bool(0), 0));
+    BOOST_CHECK_EQUAL(sizeof(uint8_t), GetSerializeSize(bool(0)));
 
     // Sanity-check GetSerializeSize and c++ type matching
-    BOOST_CHECK_EQUAL(GetSerializeSize((unsigned char)0, 0), 1U);
-    BOOST_CHECK_EQUAL(GetSerializeSize(int8_t(0), 0), 1U);
-    BOOST_CHECK_EQUAL(GetSerializeSize(uint8_t(0), 0), 1U);
-    BOOST_CHECK_EQUAL(GetSerializeSize(int16_t(0), 0), 2U);
-    BOOST_CHECK_EQUAL(GetSerializeSize(uint16_t(0), 0), 2U);
-    BOOST_CHECK_EQUAL(GetSerializeSize(int32_t(0), 0), 4U);
-    BOOST_CHECK_EQUAL(GetSerializeSize(uint32_t(0), 0), 4U);
-    BOOST_CHECK_EQUAL(GetSerializeSize(int64_t(0), 0), 8U);
-    BOOST_CHECK_EQUAL(GetSerializeSize(uint64_t(0), 0), 8U);
-    BOOST_CHECK_EQUAL(GetSerializeSize(bool(0), 0), 1U);
-    BOOST_CHECK_EQUAL(GetSerializeSize(std::array<uint8_t, 1>{0}, 0), 1U);
-    BOOST_CHECK_EQUAL(GetSerializeSize(std::array<uint8_t, 2>{0, 0}, 0), 2U);
+    BOOST_CHECK_EQUAL(GetSerializeSize((unsigned char)0), 1U);
+    BOOST_CHECK_EQUAL(GetSerializeSize(int8_t(0)), 1U);
+    BOOST_CHECK_EQUAL(GetSerializeSize(uint8_t(0)), 1U);
+    BOOST_CHECK_EQUAL(GetSerializeSize(int16_t(0)), 2U);
+    BOOST_CHECK_EQUAL(GetSerializeSize(uint16_t(0)), 2U);
+    BOOST_CHECK_EQUAL(GetSerializeSize(int32_t(0)), 4U);
+    BOOST_CHECK_EQUAL(GetSerializeSize(uint32_t(0)), 4U);
+    BOOST_CHECK_EQUAL(GetSerializeSize(int64_t(0)), 8U);
+    BOOST_CHECK_EQUAL(GetSerializeSize(uint64_t(0)), 8U);
+    BOOST_CHECK_EQUAL(GetSerializeSize(bool(0)), 1U);
+    BOOST_CHECK_EQUAL(GetSerializeSize(std::array<uint8_t, 1>{0}), 1U);
+    BOOST_CHECK_EQUAL(GetSerializeSize(std::array<uint8_t, 2>{0, 0}), 2U);
 }
 
 BOOST_AUTO_TEST_CASE(varints)
@@ -97,13 +97,13 @@ BOOST_AUTO_TEST_CASE(varints)
     DataStream::size_type size = 0;
     for (int i = 0; i < 100000; i++) {
         ss << VARINT_MODE(i, VarIntMode::NONNEGATIVE_SIGNED);
-        size += ::GetSerializeSize(VARINT_MODE(i, VarIntMode::NONNEGATIVE_SIGNED), 0);
+        size += ::GetSerializeSize(VARINT_MODE(i, VarIntMode::NONNEGATIVE_SIGNED));
         BOOST_CHECK(size == ss.size());
     }
 
     for (uint64_t i = 0;  i < 100000000000ULL; i += 999999937) {
         ss << VARINT(i);
-        size += ::GetSerializeSize(VARINT(i), 0);
+        size += ::GetSerializeSize(VARINT(i));
         BOOST_CHECK(size == ss.size());
     }
 
diff --git a/src/test/uint256_tests.cpp b/src/test/uint256_tests.cpp
index 9caefe43e23..933988dd7ad 100644
--- a/src/test/uint256_tests.cpp
+++ b/src/test/uint256_tests.cpp
@@ -184,8 +184,8 @@ BOOST_AUTO_TEST_CASE( methods ) // GetHex SetHex begin() end() size() GetLow64 G
     BOOST_CHECK(OneL.begin() + 32 == OneL.end());
     BOOST_CHECK(MaxL.begin() + 32 == MaxL.end());
     BOOST_CHECK(TmpL.begin() + 32 == TmpL.end());
-    BOOST_CHECK(GetSerializeSize(R1L, PROTOCOL_VERSION) == 32);
-    BOOST_CHECK(GetSerializeSize(ZeroL, PROTOCOL_VERSION) == 32);
+    BOOST_CHECK(GetSerializeSize(R1L) == 32);
+    BOOST_CHECK(GetSerializeSize(ZeroL) == 32);
 
     DataStream ss{};
     ss << R1L;
@@ -230,8 +230,8 @@ BOOST_AUTO_TEST_CASE( methods ) // GetHex SetHex begin() end() size() GetLow64 G
     BOOST_CHECK(OneS.begin() + 20 == OneS.end());
     BOOST_CHECK(MaxS.begin() + 20 == MaxS.end());
     BOOST_CHECK(TmpS.begin() + 20 == TmpS.end());
-    BOOST_CHECK(GetSerializeSize(R1S, PROTOCOL_VERSION) == 20);
-    BOOST_CHECK(GetSerializeSize(ZeroS, PROTOCOL_VERSION) == 20);
+    BOOST_CHECK(GetSerializeSize(R1S) == 20);
+    BOOST_CHECK(GetSerializeSize(ZeroS) == 20);
 
     ss << R1S;
     BOOST_CHECK(ss.str() == std::string(R1Array,R1Array+20));
diff --git a/src/test/util/setup_common.h b/src/test/util/setup_common.h
index 4e1a26f3039..b60cf7e4fdc 100644
--- a/src/test/util/setup_common.h
+++ b/src/test/util/setup_common.h
@@ -17,6 +17,7 @@
 #include <util/fs.h>
 #include <util/string.h>
 #include <util/vector.h>
+#include <version.h>
 
 #include <functional>
 #include <type_traits>
diff --git a/src/undo.h b/src/undo.h
index a98f046735c..1fb9ac06880 100644
--- a/src/undo.h
+++ b/src/undo.h
@@ -11,7 +11,6 @@
 #include <consensus/consensus.h>
 #include <primitives/transaction.h>
 #include <serialize.h>
-#include <version.h>
 
 /** Formatter for undo information for a CTxIn
  *
diff --git a/src/wallet/rpc/spend.cpp b/src/wallet/rpc/spend.cpp
index 0f7a8820349..65195046185 100644
--- a/src/wallet/rpc/spend.cpp
+++ b/src/wallet/rpc/spend.cpp
@@ -19,6 +19,7 @@
 #include <wallet/rpc/util.h>
 #include <wallet/spend.h>
 #include <wallet/wallet.h>
+#include <version.h>
 
 #include <univalue.h>
 
diff --git a/src/wallet/spend.cpp b/src/wallet/spend.cpp
index b573062d32a..d586f6d4aa5 100644
--- a/src/wallet/spend.cpp
+++ b/src/wallet/spend.cpp
@@ -1081,7 +1081,7 @@ static util::Result<CreatedTransactionResult> CreateTransactionInternal(
         CTxOut txout(recipient.nAmount, GetScriptForDestination(recipient.dest));
 
         // Include the fee cost for outputs.
-        coin_selection_params.tx_noinputs_size += ::GetSerializeSize(txout, PROTOCOL_VERSION);
+        coin_selection_params.tx_noinputs_size += ::GetSerializeSize(txout);
 
         if (IsDust(txout, wallet.chain().relayDustFee())) {
             return util::Error{_("Transaction amount too small")};
diff --git a/src/zmq/zmqpublishnotifier.cpp b/src/zmq/zmqpublishnotifier.cpp
index a4fb915d718..54d125e47be 100644
--- a/src/zmq/zmqpublishnotifier.cpp
+++ b/src/zmq/zmqpublishnotifier.cpp
@@ -19,7 +19,6 @@
 #include <streams.h>
 #include <sync.h>
 #include <uint256.h>
-#include <version.h>
 #include <zmq/zmqutil.h>
 
 #include <zmq.h>