diff --git a/x-pack/plugin/rollup/src/main/java/org/elasticsearch/xpack/downsample/RollupShardTaskParams.java b/x-pack/plugin/rollup/src/main/java/org/elasticsearch/xpack/downsample/RollupShardTaskParams.java
index 003bd68088bac..6626ad3557d7e 100644
--- a/x-pack/plugin/rollup/src/main/java/org/elasticsearch/xpack/downsample/RollupShardTaskParams.java
+++ b/x-pack/plugin/rollup/src/main/java/org/elasticsearch/xpack/downsample/RollupShardTaskParams.java
@@ -116,7 +116,7 @@ public static RollupShardTaskParams readFromStream(final StreamInput in) throws
             in.readString(),
             in.readVLong(),
             in.readVLong(),
-            ShardId.fromString(in.readString()),
+            new ShardId(in),
             in.readStringArray(),
             in.readStringArray()
         );