diff --git a/cmd/mtredisalize/changetracker.go b/cmd/mtredisalize/changetracker.go
index 53a3c1f..413d4d0 100644
--- a/cmd/mtredisalize/changetracker.go
+++ b/cmd/mtredisalize/changetracker.go
@@ -41,7 +41,7 @@ func (ct *ChangeTracker) BlockChanged(key []byte) {
 	ct.mutex.Unlock()
 }
 
-func (ct *ChangeTracker) FlushChanges(url string) (err error) {
+func (ct *ChangeTracker) FlushChanges(url string) {
 	var oldChanges map[quantizedXZ]bool
 	ct.mutex.Lock()
 	if len(ct.changes) > 0 {
@@ -59,6 +59,7 @@ func (ct *ChangeTracker) FlushChanges(url string) (err error) {
 			changes[i] = change
 			i++
 		}
+		var err error
 		var buf bytes.Buffer
 		encoder := json.NewEncoder(&buf)
 		if err = encoder.Encode(changes); err != nil {