diff --git a/params.go b/params.go
index fa468698..1ce1fec2 100644
--- a/params.go
+++ b/params.go
@@ -26,6 +26,11 @@ type Params struct {
 	// have represented in compact form.  See CompactToBig for more details
 	// on compact form.
 	PowLimitBits uint32
+
+	// SubsidyHalvingInterval is the interval of blocks at which the
+	// baseSubsidy is continually halved.  Mathematically this is:
+	// baseSubsidy / 2^(height/SubsidyHalvingInterval)
+	SubsidyHalvingInterval int64
 }
 
 // mainPowLimit is the highest proof of work value a bitcoin block can have for
@@ -35,10 +40,11 @@ var mainPowLimit = new(big.Int).Sub(new(big.Int).Lsh(bigOne, 224), bigOne)
 // mainNetParams contains parameters specific to the main network
 // (btcwire.MainNet).
 var mainNetParams = Params{
-	GenesisBlock: &btcwire.GenesisBlock,
-	GenesisHash:  &btcwire.GenesisHash,
-	PowLimit:     mainPowLimit,
-	PowLimitBits: BigToCompact(mainPowLimit),
+	GenesisBlock:           &btcwire.GenesisBlock,
+	GenesisHash:            &btcwire.GenesisHash,
+	PowLimit:               mainPowLimit,
+	PowLimitBits:           BigToCompact(mainPowLimit),
+	SubsidyHalvingInterval: 210000,
 }
 
 // regressionPowLimit is the highest proof of work value a bitcoin block can
@@ -48,10 +54,11 @@ var regressionPowLimit = new(big.Int).Sub(new(big.Int).Lsh(bigOne, 255), bigOne)
 // regressionParams contains parameters specific to the regression test network
 // (btcwire.TestNet).
 var regressionParams = Params{
-	GenesisBlock: &btcwire.TestNetGenesisBlock,
-	GenesisHash:  &btcwire.TestNetGenesisHash,
-	PowLimit:     regressionPowLimit,
-	PowLimitBits: BigToCompact(regressionPowLimit),
+	GenesisBlock:           &btcwire.TestNetGenesisBlock,
+	GenesisHash:            &btcwire.TestNetGenesisHash,
+	PowLimit:               regressionPowLimit,
+	PowLimitBits:           BigToCompact(regressionPowLimit),
+	SubsidyHalvingInterval: 150,
 }
 
 // testNetPowLimit is the highest proof of work value a bitcoin block can have
@@ -61,10 +68,11 @@ var testNetPowLimit = new(big.Int).Sub(new(big.Int).Lsh(bigOne, 224), bigOne)
 // testNet3Params contains parameters specific to the test network (version 3)
 // (btcwire.TestNet3).
 var testNet3Params = Params{
-	GenesisBlock: &btcwire.TestNet3GenesisBlock,
-	GenesisHash:  &btcwire.TestNet3GenesisHash,
-	PowLimit:     testNetPowLimit,
-	PowLimitBits: BigToCompact(testNetPowLimit),
+	GenesisBlock:           &btcwire.TestNet3GenesisBlock,
+	GenesisHash:            &btcwire.TestNet3GenesisHash,
+	PowLimit:               testNetPowLimit,
+	PowLimitBits:           BigToCompact(testNetPowLimit),
+	SubsidyHalvingInterval: 210000,
 }
 
 // chainParams returns chain parameters specific to the bitcoin network
diff --git a/validate.go b/validate.go
index 28555404..703741e1 100644
--- a/validate.go
+++ b/validate.go
@@ -43,13 +43,8 @@ const (
 	serializedHeightVersion = 2
 
 	// baseSubsidy is the starting subsidy amount for mined blocks.  This
-	// value is halved every subsidyHalvingInterval blocks.
+	// value is halved every SubsidyHalvingInterval blocks.
 	baseSubsidy = 50 * btcutil.SatoshiPerBitcoin
-
-	// subsidyHalvingInterval is the interval of blocks at which the
-	// baseSubsidy is continually halved.  See calcBlockSubsidy for more
-	// details.
-	subsidyHalvingInterval = 210000
 )
 
 var (
@@ -162,14 +157,14 @@ func isBIP0030Node(node *blockNode) bool {
 // newly generated blocks awards as well as validating the coinbase for blocks
 // has the expected value.
 //
-// The subsidy is halved every subsidyHalvingInterval blocks.  Mathematically
-// this is: baseSubsidy / 2^(height/subsidyHalvingInterval)
+// The subsidy is halved every SubsidyHalvingInterval blocks.  Mathematically
+// this is: baseSubsidy / 2^(height/SubsidyHalvingInterval)
 //
 // At the target block generation rate this is approximately every 4
 // years.
-func calcBlockSubsidy(height int64) int64 {
+func (b *BlockChain) calcBlockSubsidy(height int64) int64 {
 	// Equivalent to: baseSubsidy / 2^(height/subsidyHalvingInterval)
-	return baseSubsidy >> uint(height/subsidyHalvingInterval)
+	return baseSubsidy >> uint(height/b.chainParams().SubsidyHalvingInterval)
 }
 
 // CheckTransactionSanity performs some preliminary checks on a transaction to
@@ -824,7 +819,7 @@ func (b *BlockChain) checkConnectBlock(node *blockNode, block *btcutil.Block) er
 	for _, txOut := range transactions[0].MsgTx().TxOut {
 		totalSatoshiOut += txOut.Value
 	}
-	expectedSatoshiOut := calcBlockSubsidy(node.height) + totalFees
+	expectedSatoshiOut := b.calcBlockSubsidy(node.height) + totalFees
 	if totalSatoshiOut > expectedSatoshiOut {
 		str := fmt.Sprintf("coinbase transaction for block pays %v "+
 			"which is more than expected value of %v",