diff --git a/mempool.go b/mempool.go
index 376eb71e..380b1a54 100644
--- a/mempool.go
+++ b/mempool.go
@@ -370,16 +370,17 @@ func checkInputsStandard(tx *btcutil.Tx, txStore btcchain.TxStore) error {
 	return nil
 }
 
-// calcTxFee returns the minimum transaction fee required for the passed
-// transaction.
-func calcTxFee(size int) int64 {
+// calcMinRequiredTxRelayFee returns the minimum transaction fee required for a
+// transaction with the passed serialized size to be accepted into the memory
+// pool and relayed.
+func calcMinRequiredTxRelayFee(serializedSize int64) int64 {
 	// Calculate the minimum fee for a transaction to be allowed into the
 	// mempool and relayed by scaling the base fee (which is the minimum
 	// free transaction relay fee).  minTxRelayFee is in Satoshi/KB, so
 	// divide the transaction size by 1000 to convert to kilobytes.  Also,
 	// integer division is used so fees only increase on full kilobyte
 	// boundaries.
-	minFee := (1 + size/1000) * minTxRelayFee
+	minFee := (1 + serializedSize/1000) * minTxRelayFee
 
 	// Set the minimum fee to the maximum possible value if the calculated
 	// fee is not in the valid range for monetary amounts.
@@ -387,26 +388,7 @@ func calcTxFee(size int) int64 {
 		minFee = btcutil.MaxSatoshi
 	}
 
-	return int64(minFee)
-}
-
-// calcMinRelayFee retuns the minimum transaction fee required for the passed
-// transaction to be accepted into the memory pool and relayed.
-func calcMinTxRelayFee(size int) int64 {
-	// Most miners allow a free transaction area in blocks they mine to go
-	// alongside the area used for high-priority transactions as well as
-	// transactions with fees.  A transaction size of up to 1000 bytes is
-	// considered safe to go into this section.  Further, the minimum fee
-	// calculated below on its own would encourage several small
-	// transactions to avoid fees rather than one single larger transaction
-	// which is more desirable.  Therefore, as long as the size of the
-	// transaction does not exceeed 1000 less than the reserved space for
-	// high-priority transactions, don't require a fee for it.
-	if size < (defaultBlockPrioritySize - 1000) {
-		return 0
-	}
-
-	return calcTxFee(size)
+	return minFee
 }
 
 // removeOrphan removes the passed orphan transaction from the orphan pool and
@@ -895,18 +877,28 @@ func (mp *txMemPool) maybeAcceptTransaction(tx *btcutil.Tx, isOrphan *bool, isNe
 	// reasonable number of ECDSA signature verifications.
 
 	// Don't allow transactions with fees too low to get into a mined block.
-	serializedSize := tx.MsgTx().SerializeSize()
-	minRequiredFee := calcMinTxRelayFee(serializedSize)
-	if txFee < minRequiredFee {
+	//
+	// Most miners allow a free transaction area in blocks they mine to go
+	// alongside the area used for high-priority transactions as well as
+	// transactions with fees.  A transaction size of up to 1000 bytes is
+	// considered safe to go into this section.  Further, the minimum fee
+	// calculated below on its own would encourage several small
+	// transactions to avoid fees rather than one single larger transaction
+	// which is more desirable.  Therefore, as long as the size of the
+	// transaction does not exceeed 1000 less than the reserved space for
+	// high-priority transactions, don't require a fee for it.
+	serializedSize := int64(tx.MsgTx().SerializeSize())
+	minFee := calcMinRequiredTxRelayFee(serializedSize)
+	if serializedSize >= (defaultBlockPrioritySize-1000) && txFee < minFee {
 		str := fmt.Sprintf("transaction %v has %d fees which is under "+
 			"the required amount of %d", txHash, txFee,
-			minRequiredFee)
+			minFee)
 		return txRuleError(btcwire.RejectInsufficientFee, str)
 	}
 
 	// Free-to-relay transactions are rate limited here to prevent
 	// penny-flooding with tiny transactions as a form of attack.
-	if rateLimit && txFee < calcTxFee(serializedSize) {
+	if rateLimit && txFee < minFee {
 		nowUnix := time.Now().Unix()
 		// we decay passed data with an exponentially decaying ~10
 		// minutes window - matches bitcoind handling.