diff --git a/lib/merge-data.js b/lib/merge-data.js
index 9a48451..540e9c6 100644
--- a/lib/merge-data.js
+++ b/lib/merge-data.js
@@ -258,9 +258,9 @@ const mergeDataList = async (dataList, options) => {
 
     const artifacts = await mergeArtifacts(artifactsList, options);
 
-    // base on first one
+    // base on first one, do not change dataList (need for onData)
     const mergedData = {
-        ... dataList.shift()
+        ... dataList[0]
     };
 
     // merge new options