diff --git a/cmd/consumer/main.go b/cmd/consumer/main.go
index acb6de8..4602c13 100644
--- a/cmd/consumer/main.go
+++ b/cmd/consumer/main.go
@@ -31,7 +31,7 @@ func (srp *SampleRecordProcessor) Initialize(shardID string) error {
 	return nil
 }
 
-func (srp *SampleRecordProcessor) checkpoint(checkpointer kcl.Checkpointer, sequenceNumber string, subSequenceNumber int) {
+func (srp *SampleRecordProcessor) checkpoint(checkpointer kcl.Checkpointer, sequenceNumber *string, subSequenceNumber *int) {
 	for n := -1; n < srp.checkpointRetries; n++ {
 		err := checkpointer.Checkpoint(sequenceNumber, subSequenceNumber)
 		if err == nil {
@@ -79,7 +79,8 @@ func (srp *SampleRecordProcessor) ProcessRecords(records []kcl.Record, checkpoin
 		}
 	}
 	if time.Now().Sub(srp.lastCheckpoint) > srp.checkpointFreq {
-		srp.checkpoint(checkpointer, srp.largestSeq.String(), srp.largestSubSeq)
+		largestSeq := srp.largestSeq.String()
+		srp.checkpoint(checkpointer, &largestSeq, &srp.largestSubSeq)
 		srp.lastCheckpoint = time.Now()
 	}
 	return nil
@@ -88,7 +89,7 @@ func (srp *SampleRecordProcessor) ProcessRecords(records []kcl.Record, checkpoin
 func (srp *SampleRecordProcessor) Shutdown(checkpointer kcl.Checkpointer, reason string) error {
 	if reason == "TERMINATE" {
 		fmt.Fprintf(os.Stderr, "Was told to terminate, will attempt to checkpoint.\n")
-		srp.checkpoint(checkpointer, "", 0)
+		srp.checkpoint(checkpointer, nil, nil)
 	} else {
 		fmt.Fprintf(os.Stderr, "Shutting down due to failover. Will not checkpoint.\n")
 	}
diff --git a/kcl/kcl.go b/kcl/kcl.go
index ca38f2e..a9f4d9c 100644
--- a/kcl/kcl.go
+++ b/kcl/kcl.go
@@ -38,7 +38,7 @@ func (ce CheckpointError) Error() string {
 	return ce.e
 }
 
-func (c Checkpointer) Checkpoint(sequenceNumber string, subSequenceNumber int) error {
+func (c Checkpointer) Checkpoint(sequenceNumber *string, subSequenceNumber *int) error {
 	c.ioHandler.writeAction(ActionCheckpoint{
 		Action:            "checkpoint",
 		SequenceNumber:    sequenceNumber,
@@ -56,9 +56,9 @@ func (c Checkpointer) Checkpoint(sequenceNumber string, subSequenceNumber int) e
 	if !ok {
 		return fmt.Errorf("expected checkpoint response, got '%s'", line.String())
 	}
-	if action.Error != "" {
+	if action.Error != nil && *action.Error != "" {
 		return CheckpointError{
-			e: action.Error,
+			e: *action.Error,
 		}
 	}
 	return nil
@@ -117,10 +117,10 @@ type ActionShutdown struct {
 }
 
 type ActionCheckpoint struct {
-	Action            string `json:"action"`
-	SequenceNumber    string `json:"sequenceNumber"`
-	SubSequenceNumber int    `json:"subSequenceNumber"`
-	Error             string `json:"error"`
+	Action            string  `json:"action"`
+	SequenceNumber    *string `json:"sequenceNumber,omitempty"`
+	SubSequenceNumber *int    `json:"subSequenceNumber,omitempty"`
+	Error             *string `json:"error,omitempty"`
 }
 
 func (i ioHandler) loadAction(line string) (interface{}, error) {