diff --git a/src/bitcoin-tx.cpp b/src/bitcoin-tx.cpp
--- a/src/bitcoin-tx.cpp
+++ b/src/bitcoin-tx.cpp
@@ -242,7 +242,7 @@
         throw std::runtime_error("invalid TX input txid");
     }
 
-    uint256 txid(uint256S(strTxid));
+    TxId txid(uint256S(strTxid));
 
     static const unsigned int minTxOutSz = 9;
     static const unsigned int maxVout = MAX_TX_SIZE / minTxOutSz;
diff --git a/src/primitives/transaction.h b/src/primitives/transaction.h
--- a/src/primitives/transaction.h
+++ b/src/primitives/transaction.h
@@ -123,9 +123,9 @@
     explicit CTxIn(COutPoint prevoutIn, CScript scriptSigIn = CScript(),
                    uint32_t nSequenceIn = SEQUENCE_FINAL)
         : prevout(prevoutIn), scriptSig(scriptSigIn), nSequence(nSequenceIn) {}
-    CTxIn(uint256 hashPrevTx, uint32_t nOut, CScript scriptSigIn = CScript(),
+    CTxIn(TxId prevTxId, uint32_t nOut, CScript scriptSigIn = CScript(),
           uint32_t nSequenceIn = SEQUENCE_FINAL)
-        : CTxIn(COutPoint(hashPrevTx, nOut), scriptSigIn, nSequenceIn) {}
+        : CTxIn(COutPoint(prevTxId, nOut), scriptSigIn, nSequenceIn) {}
 
     ADD_SERIALIZE_METHODS;
 
diff --git a/src/validation.cpp b/src/validation.cpp
--- a/src/validation.cpp
+++ b/src/validation.cpp
@@ -742,7 +742,7 @@
     AssertLockHeld(cs_main);
 
     const CTransaction &tx = *ptx;
-    const uint256 txid = tx.GetId();
+    const TxId txid = tx.GetId();
     if (pfMissingInputs) {
         *pfMissingInputs = false;
     }