diff --git a/redistimeseries/src/main/java/io/github/dengliming/redismodule/redistimeseries/RedisTimeSeries.java b/redistimeseries/src/main/java/io/github/dengliming/redismodule/redistimeseries/RedisTimeSeries.java
index 2a86928..5e0bec7 100644
--- a/redistimeseries/src/main/java/io/github/dengliming/redismodule/redistimeseries/RedisTimeSeries.java
+++ b/redistimeseries/src/main/java/io/github/dengliming/redismodule/redistimeseries/RedisTimeSeries.java
@@ -106,7 +106,7 @@ public RFuture<Long> addAsync(Sample sample, TimeSeriesOptions options) {
 
         List<Object> args = new ArrayList<>();
         args.add(sample.getKey());
-        args.add(sample.getValue().getTimestamp());
+        args.add(sample.getValue().getTimestamp() > 0 ? sample.getValue().getTimestamp() : "*");
         args.add(sample.getValue().getValue());
         if (options != null) {
             options.isAdd(true).build(args);