diff --git a/processor.go b/processor.go
index 2ec4745..e7d41e0 100644
--- a/processor.go
+++ b/processor.go
@@ -82,12 +82,14 @@ func (p *processor) exec() {
 	task := &Task{Type: msg.Type, Payload: msg.Payload}
 	p.sema <- struct{}{} // acquire token
 	go func(task *Task) {
-		defer func() {
-			if err := p.rdb.lrem(inProgress, msg); err != nil {
+		// NOTE: This deferred anonymous function needs to take taskMessage as a value because
+		// the message can be mutated by the time this function is called.
+		defer func(msg taskMessage) {
+			if err := p.rdb.lrem(inProgress, &msg); err != nil {
 				log.Printf("[ERROR] could not remove %+v from %q: %v\n", msg, inProgress, err)
 			}
 			<-p.sema // release token
-		}()
+		}(*msg)
 		err := perform(p.handler, task)
 		if err != nil {
 			retryTask(p.rdb, msg, err)