diff --git a/wtxmgr/tx.go b/wtxmgr/tx.go
index a9b9651..0b232ea 100644
--- a/wtxmgr/tx.go
+++ b/wtxmgr/tx.go
@@ -405,10 +405,16 @@ func (s *Store) AddCredit(ns walletdb.ReadWriteBucket, rec *TxRecord, block *Blo
 // duplicate (false).
 func (s *Store) addCredit(ns walletdb.ReadWriteBucket, rec *TxRecord, block *BlockMeta, index uint32, change bool) (bool, error) {
 	if block == nil {
+		// If the outpoint that we should mark as credit already exists
+		// within the store, either as unconfirmed or confirmed, then we
+		// have nothing left to do and can exit.
 		k := canonicalOutPoint(&rec.Hash, index)
 		if existsRawUnminedCredit(ns, k) != nil {
 			return false, nil
 		}
+		if existsRawUnspent(ns, k) != nil {
+			return false, nil
+		}
 		v := valueUnminedCredit(btcutil.Amount(rec.MsgTx.TxOut[index].Value), change)
 		return true, putRawUnminedCredit(ns, k, v)
 	}
diff --git a/wtxmgr/unconfirmed.go b/wtxmgr/unconfirmed.go
index 812d2d2..37bf7e1 100644
--- a/wtxmgr/unconfirmed.go
+++ b/wtxmgr/unconfirmed.go
@@ -14,12 +14,25 @@ import (
 // insertMemPoolTx inserts the unmined transaction record.  It also marks
 // previous outputs referenced by the inputs as spent.
 func (s *Store) insertMemPoolTx(ns walletdb.ReadWriteBucket, rec *TxRecord) error {
-	v := existsRawUnmined(ns, rec.Hash[:])
-	if v != nil {
-		// TODO: compare serialized txs to ensure this isn't a hash collision?
+	// Check whether the transaction has already been added to the
+	// unconfirmed bucket.
+	if existsRawUnmined(ns, rec.Hash[:]) != nil {
+		// TODO: compare serialized txs to ensure this isn't a hash
+		// collision?
 		return nil
 	}
 
+	// Since transaction records within the store are keyed by their
+	// transaction _and_ block confirmation, we'll iterate through the
+	// transaction's outputs to determine if we've already seen them to
+	// prevent from adding this transaction to the unconfirmed bucket.
+	for i := range rec.MsgTx.TxOut {
+		k := canonicalOutPoint(&rec.Hash, uint32(i))
+		if existsRawUnspent(ns, k) != nil {
+			return nil
+		}
+	}
+
 	log.Infof("Inserting unconfirmed transaction %v", rec.Hash)
 	v, err := valueTxRecord(rec)
 	if err != nil {