diff --git a/error.go b/error.go
index 974d33c9..31853c59 100644
--- a/error.go
+++ b/error.go
@@ -62,10 +62,14 @@ const (
 	// checkpoint height does not match the expected one.
 	ErrBadCheckpoint
 
-	// ErrForkTooOld indicates a block is attempted to fork the block chain
+	// ErrForkTooOld indicates a block is attempting to fork the block chain
 	// before the most recent checkpoint.
 	ErrForkTooOld
 
+	// ErrCheckpointTimeTooOld indicates a block has a timestamp before the
+	// most recent checkpoint.
+	ErrCheckpointTimeTooOld
+
 	// ErrNoTransactions indicates the block does not have a least one
 	// transaction.  A valid block must have at least the coinbase
 	// transaction.
@@ -190,6 +194,7 @@ var errorCodeStrings = map[ErrorCode]string{
 	ErrBadMerkleRoot:         "ErrBadMerkleRoot",
 	ErrBadCheckpoint:         "ErrBadCheckpoint",
 	ErrForkTooOld:            "ErrForkTooOld",
+	ErrCheckpointTimeTooOld:  "ErrCheckpointTimeTooOld",
 	ErrNoTransactions:        "ErrNoTransactions",
 	ErrTooManyTransactions:   "ErrTooManyTransactions",
 	ErrNoTxInputs:            "ErrNoTxInputs",
diff --git a/error_test.go b/error_test.go
index 20f6f58c..4f7b3398 100644
--- a/error_test.go
+++ b/error_test.go
@@ -28,6 +28,7 @@ func TestErrorCodeStringer(t *testing.T) {
 		{btcchain.ErrBadMerkleRoot, "ErrBadMerkleRoot"},
 		{btcchain.ErrBadCheckpoint, "ErrBadCheckpoint"},
 		{btcchain.ErrForkTooOld, "ErrForkTooOld"},
+		{btcchain.ErrCheckpointTimeTooOld, "ErrCheckpointTimeTooOld"},
 		{btcchain.ErrNoTransactions, "ErrNoTransactions"},
 		{btcchain.ErrTooManyTransactions, "ErrTooManyTransactions"},
 		{btcchain.ErrNoTxInputs, "ErrNoTxInputs"},
diff --git a/process.go b/process.go
index e86103b1..55927afd 100644
--- a/process.go
+++ b/process.go
@@ -165,7 +165,7 @@ func (b *BlockChain) ProcessBlock(block *btcutil.Block, flags BehaviorFlags) (bo
 			str := fmt.Sprintf("block %v has timestamp %v before "+
 				"last checkpoint timestamp %v", blockHash,
 				blockHeader.Timestamp, checkpointTime)
-			return false, ruleError(ErrTimeTooOld, str)
+			return false, ruleError(ErrCheckpointTimeTooOld, str)
 		}
 		if !fastAdd {
 			// Even though the checks prior to now have already ensured the