diff --git a/consumer.go b/consumer.go
index e28fe67..4777356 100644
--- a/consumer.go
+++ b/consumer.go
@@ -299,10 +299,10 @@ func (c *Consumer) getShardIterator(ctx context.Context, streamName, shardID, se
 }
 
 func isRetriableError(err error) bool {
-	if oe := (*types.ExpiredIteratorException)(nil); errors.As(err, &oe) {
+	switch err.(type) {
+	case *types.ExpiredIteratorException:
 		return true
-	}
-	if oe := (*types.ProvisionedThroughputExceededException)(nil); errors.As(err, &oe) {
+	case *types.ProvisionedThroughputExceededException:
 		return true
 	}
 	return false