diff --git a/src/Stratis.Bitcoin.Features.Consensus/CoinViews/CoinviewHelper.cs b/src/Stratis.Bitcoin.Features.Consensus/CoinViews/CoinviewHelper.cs
index bc3f268f2a..c8b041204e 100644
--- a/src/Stratis.Bitcoin.Features.Consensus/CoinViews/CoinviewHelper.cs
+++ b/src/Stratis.Bitcoin.Features.Consensus/CoinViews/CoinviewHelper.cs
@@ -20,8 +20,10 @@ public OutPoint[] GetIdsToFetch(Block block, bool enforceBIP30)
             {
                 if (enforceBIP30)
                 {
+                    // Calculate the hash outside the loop.
+                    var txId = tx.GetHash();
                     foreach (var utxo in tx.Outputs.AsIndexedOutputs())
-                        ids.Add(utxo.ToOutPoint());
+                        ids.Add(new OutPoint() { Hash = txId, N = utxo.N });
                 }
 
                 if (!tx.IsCoinBase)
diff --git a/src/Stratis.Bitcoin.Features.Consensus/UnspentOutputSet.cs b/src/Stratis.Bitcoin.Features.Consensus/UnspentOutputSet.cs
index 41b71318de..2aa58e4ce2 100644
--- a/src/Stratis.Bitcoin.Features.Consensus/UnspentOutputSet.cs
+++ b/src/Stratis.Bitcoin.Features.Consensus/UnspentOutputSet.cs
@@ -52,9 +52,12 @@ public void Update(Network network, Transaction transaction, int height)
                 }
             }
 
-            foreach (IndexedTxOut output in transaction.Outputs.AsIndexedOutputs())
+            // Hash calculations are slow. Do this one outside the loop...
+            var txHash = transaction.GetHash();
+
+            foreach (IndexedTxOut output in transaction.Outputs.AsIndexedOutputs().ToList())
             {
-                var outpoint = output.ToOutPoint();
+                var outpoint = new OutPoint() { Hash = txHash, N = output.N };
                 var coinbase = transaction.IsCoinBase;
                 var coinstake = network.Consensus.IsProofOfStake ? transaction.IsCoinStake : false;