diff --git a/pkg/retry/retry.go b/pkg/retry/retry.go
index 33469273..c3e0c70b 100644
--- a/pkg/retry/retry.go
+++ b/pkg/retry/retry.go
@@ -17,6 +17,8 @@ type IsRetryable func(error) bool
 type Settings struct {
 	// Timeout lets WithBackoff give up once elapsed (if >0).
 	Timeout time.Duration
+	// OnError is called if an error occurs.
+	OnError func(elapsed time.Duration, attempt uint64, err, lastErr error)
 }
 
 // WithBackoff retries the passed function if it fails and the error allows it to retry.
@@ -30,13 +32,18 @@ func WithBackoff(
 		defer cancelCtx()
 	}
 
-	for attempt := 0; ; /* true */ attempt++ {
+	start := time.Now()
+	for attempt := uint64(0); ; /* true */ attempt++ {
 		prevErr := err
 
 		if err = retryableFunc(ctx); err == nil {
 			return
 		}
 
+		if settings.OnError != nil {
+			settings.OnError(time.Since(start), attempt, err, prevErr)
+		}
+
 		isRetryable := retryable(err)
 
 		if prevErr != nil && (errors.Is(err, context.DeadlineExceeded) || errors.Is(err, context.Canceled)) {
@@ -49,7 +56,7 @@ func WithBackoff(
 			return
 		}
 
-		sleep := b(uint64(attempt))
+		sleep := b(attempt)
 		select {
 		case <-ctx.Done():
 			if err == nil {