diff --git a/src/Makefile.am b/src/Makefile.am
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -142,6 +142,7 @@
   rpc/misc.h \
   rpc/protocol.h \
   rpc/server.h \
+  rpc/tojson.h \
   rpc/register.h \
   scheduler.h \
   script/scriptcache.h \
diff --git a/src/rest.cpp b/src/rest.cpp
--- a/src/rest.cpp
+++ b/src/rest.cpp
@@ -11,6 +11,7 @@
 #include "primitives/transaction.h"
 #include "rpc/blockchain.h"
 #include "rpc/server.h"
+#include "rpc/tojson.h"
 #include "streams.h"
 #include "sync.h"
 #include "txmempool.h"
@@ -57,15 +58,8 @@
     }
 };
 
-extern void TxToJSON(const CTransaction &tx, const uint256 hashBlock,
-                     UniValue &entry);
-extern UniValue blockToJSON(const CBlock &block, const CBlockIndex *blockindex,
-                            bool txDetails = false);
 extern UniValue mempoolInfoToJSON();
 extern UniValue mempoolToJSON(bool fVerbose = false);
-extern void ScriptPubKeyToJSON(const CScript &scriptPubKey, UniValue &out,
-                               bool fIncludeHex);
-extern UniValue blockheaderToJSON(const CBlockIndex *blockindex);
 
 static bool RESTERR(HTTPRequest *req, enum HTTPStatusCode status,
                     std::string message) {
@@ -272,7 +266,8 @@
         }
 
         case RF_JSON: {
-            UniValue objBlock = blockToJSON(block, pblockindex, showTxDetails);
+            UniValue objBlock =
+                blockToJSON(config, block, pblockindex, showTxDetails);
             std::string strJSON = objBlock.write() + "\n";
             req->WriteHeader("Content-Type", "application/json");
             req->WriteReply(HTTP_OK, strJSON);
@@ -429,7 +424,7 @@
 
         case RF_JSON: {
             UniValue objTx(UniValue::VOBJ);
-            TxToJSON(*tx, hashBlock, objTx);
+            TxToJSON(config, *tx, hashBlock, objTx);
             std::string strJSON = objTx.write() + "\n";
             req->WriteHeader("Content-Type", "application/json");
             req->WriteReply(HTTP_OK, strJSON);
@@ -646,7 +641,7 @@
 
                 // include the script in a json output
                 UniValue o(UniValue::VOBJ);
-                ScriptPubKeyToJSON(coin.out.scriptPubKey, o, true);
+                ScriptPubKeyToJSON(config, coin.out.scriptPubKey, o, true);
                 utxo.push_back(Pair("scriptPubKey", o));
                 utxos.push_back(utxo);
             }
diff --git a/src/rpc/blockchain.cpp b/src/rpc/blockchain.cpp
--- a/src/rpc/blockchain.cpp
+++ b/src/rpc/blockchain.cpp
@@ -16,6 +16,7 @@
 #include "policy/policy.h"
 #include "primitives/transaction.h"
 #include "rpc/server.h"
+#include "rpc/tojson.h"
 #include "streams.h"
 #include "sync.h"
 #include "txmempool.h"
@@ -23,11 +24,10 @@
 #include "utilstrencodings.h"
 #include "validation.h"
 
-#include <cstdint>
-
 #include <boost/thread/thread.hpp> // boost::thread::interrupt
 
 #include <condition_variable>
+#include <cstdint>
 #include <mutex>
 
 struct CUpdatedBlock {
@@ -39,11 +39,6 @@
 static std::condition_variable cond_blockchange;
 static CUpdatedBlock latestblock;
 
-extern void TxToJSON(const CTransaction &tx, const uint256 hashBlock,
-                     UniValue &entry);
-void ScriptPubKeyToJSON(const CScript &scriptPubKey, UniValue &out,
-                        bool fIncludeHex);
-
 static double GetDifficultyFromBits(uint32_t nBits) {
     int nShift = (nBits >> 24) & 0xff;
     double dDiff = 0x0000ffff / double(nBits & 0x00ffffff);
@@ -104,8 +99,8 @@
     return result;
 }
 
-UniValue blockToJSON(const CBlock &block, const CBlockIndex *blockindex,
-                     bool txDetails = false) {
+UniValue blockToJSON(const Config &config, const CBlock &block,
+                     const CBlockIndex *blockindex, bool txDetails) {
     UniValue result(UniValue::VOBJ);
     result.push_back(Pair("hash", blockindex->GetBlockHash().GetHex()));
     int confirmations = -1;
@@ -124,10 +119,11 @@
     for (const auto &tx : block.vtx) {
         if (txDetails) {
             UniValue objTx(UniValue::VOBJ);
-            TxToJSON(*tx, uint256(), objTx);
+            TxToJSON(config, *tx, uint256(), objTx);
             txs.push_back(objTx);
-        } else
+        } else {
             txs.push_back(tx->GetId().GetHex());
+        }
     }
     result.push_back(Pair("tx", txs));
     result.push_back(Pair("time", block.GetBlockTime()));
@@ -851,7 +847,7 @@
         return strHex;
     }
 
-    return blockToJSON(block, pblockindex);
+    return blockToJSON(config, block, pblockindex);
 }
 
 struct CCoinsStats {
@@ -1116,7 +1112,7 @@
     }
     ret.push_back(Pair("value", ValueFromAmount(coin.GetTxOut().nValue)));
     UniValue o(UniValue::VOBJ);
-    ScriptPubKeyToJSON(coin.GetTxOut().scriptPubKey, o, true);
+    ScriptPubKeyToJSON(config, coin.GetTxOut().scriptPubKey, o, true);
     ret.push_back(Pair("scriptPubKey", o));
     ret.push_back(Pair("coinbase", coin.IsCoinBase()));
 
diff --git a/src/rpc/rawtransaction.cpp b/src/rpc/rawtransaction.cpp
--- a/src/rpc/rawtransaction.cpp
+++ b/src/rpc/rawtransaction.cpp
@@ -17,6 +17,7 @@
 #include "policy/policy.h"
 #include "primitives/transaction.h"
 #include "rpc/server.h"
+#include "rpc/tojson.h"
 #include "script/script.h"
 #include "script/script_error.h"
 #include "script/sign.h"
@@ -33,8 +34,8 @@
 
 #include <univalue.h>
 
-void ScriptPubKeyToJSON(const CScript &scriptPubKey, UniValue &out,
-                        bool fIncludeHex) {
+void ScriptPubKeyToJSON(const Config &config, const CScript &scriptPubKey,
+                        UniValue &out, bool fIncludeHex) {
     txnouttype type;
     std::vector<CTxDestination> addresses;
     int nRequired;
@@ -61,8 +62,8 @@
     out.push_back(Pair("addresses", a));
 }
 
-void TxToJSON(const CTransaction &tx, const uint256 hashBlock,
-              UniValue &entry) {
+void TxToJSON(const Config &config, const CTransaction &tx,
+              const uint256 hashBlock, UniValue &entry) {
     entry.push_back(Pair("txid", tx.GetId().GetHex()));
     entry.push_back(Pair("hash", tx.GetHash().GetHex()));
     entry.push_back(Pair(
@@ -99,7 +100,7 @@
         out.push_back(Pair("value", ValueFromAmount(txout.nValue)));
         out.push_back(Pair("n", (int64_t)i));
         UniValue o(UniValue::VOBJ);
-        ScriptPubKeyToJSON(txout.scriptPubKey, o, true);
+        ScriptPubKeyToJSON(config, txout.scriptPubKey, o, true);
         out.push_back(Pair("scriptPubKey", o));
         vout.push_back(out);
     }
@@ -250,7 +251,7 @@
 
     UniValue result(UniValue::VOBJ);
     result.push_back(Pair("hex", strHex));
-    TxToJSON(*tx, hashBlock, result);
+    TxToJSON(config, *tx, hashBlock, result);
     return result;
 }
 
@@ -636,7 +637,7 @@
     }
 
     UniValue result(UniValue::VOBJ);
-    TxToJSON(CTransaction(std::move(mtx)), uint256(), result);
+    TxToJSON(config, CTransaction(std::move(mtx)), uint256(), result);
 
     return result;
 }
@@ -680,7 +681,7 @@
         // Empty scripts are valid.
     }
 
-    ScriptPubKeyToJSON(script, r, false);
+    ScriptPubKeyToJSON(config, script, r, false);
 
     UniValue type;
     type = find_value(r, "type");
diff --git a/src/rpc/tojson.h b/src/rpc/tojson.h
new file mode 100644
--- /dev/null
+++ b/src/rpc/tojson.h
@@ -0,0 +1,22 @@
+// Copyright (c) 2017 The Bitcoin developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef BITCOIN_RPCTOJSON_H
+#define BITCOIN_RPCTOJSON_H
+
+#include "uint256.h"
+
+#include <univalue.h>
+
+class CScript;
+
+void ScriptPubKeyToJSON(const Config &config, const CScript &scriptPubKey,
+                        UniValue &out, bool fIncludeHex);
+void TxToJSON(const Config &config, const CTransaction &tx,
+              const uint256 hashBlock, UniValue &entry);
+UniValue blockToJSON(const Config &config, const CBlock &block,
+                     const CBlockIndex *blockindex, bool txDetails = false);
+UniValue blockheaderToJSON(const CBlockIndex *blockindex);
+
+#endif // BITCOIN_RPCTOJSON_H