diff --git a/src/primitives/transaction.h b/src/primitives/transaction.h
--- a/src/primitives/transaction.h
+++ b/src/primitives/transaction.h
@@ -18,6 +18,7 @@
  * differentiated for type safety.
  */
 struct TxId : public uint256 {
+    TxId() : uint256() {}
     explicit TxId(const uint256 &b) : uint256(b) {}
 };
 
@@ -34,15 +35,12 @@
  */
 class COutPoint {
 private:
-    uint256 txid;
+    TxId txid;
     uint32_t n;
 
 public:
     COutPoint() { SetNull(); }
-    COutPoint(uint256 txidIn, uint32_t nIn) {
-        txid = txidIn;
-        n = nIn;
-    }
+    COutPoint(uint256 txidIn, uint32_t nIn) : txid(TxId(txidIn)), n(nIn) {}
 
     ADD_SERIALIZE_METHODS;
 
@@ -59,7 +57,7 @@
 
     bool IsNull() const { return txid.IsNull() && n == uint32_t(-1); }
 
-    TxId GetTxId() const { return TxId(txid); }
+    const TxId &GetTxId() const { return txid; }
     uint32_t GetN() const { return n; }
 
     friend bool operator<(const COutPoint &a, const COutPoint &b) {