diff --git a/GUI/Model/Device/DatafileItem.cpp b/GUI/Model/Device/DatafileItem.cpp
index 8e932035dabd405d2694d1c9c8e1991b73b6d0ba..dfa68bb16e3c35e04fa18ac014cdce0e72baceb7 100644
--- a/GUI/Model/Device/DatafileItem.cpp
+++ b/GUI/Model/Device/DatafileItem.cpp
@@ -35,7 +35,7 @@ const QString Data("Data");
 const QString InstrumentId("InstrumentId");
 const QString Name("Name");
 const QString NativeData("NativeData");
-const QString NativeDataUnits("NativeDataUnits");
+const QString NativeDataUnits("NativeDataUnits"); // obsolete since v22.0
 const QString PresentationType("PresentationType");
 
 } // namespace Tag
@@ -239,7 +239,7 @@ void DatafileItem::updateFileName()
 
 void DatafileItem::writeTo(QXmlStreamWriter* w) const
 {
-    XML::writeAttribute(w, XML::Attrib::version, uint(1));
+    XML::writeAttribute(w, XML::Attrib::version, uint(2));
 
     // NOTE: The ordering of the XML elements is important in initialization
 
@@ -258,11 +258,6 @@ void DatafileItem::writeTo(QXmlStreamWriter* w) const
     XML::writeAttribute(w, XML::Attrib::value, m_presentationType);
     w->writeEndElement();
 
-    // native data units
-    w->writeStartElement(Tag::NativeDataUnits);
-    XML::writeAttribute(w, XML::Attrib::value, m_nativeDataUnits);
-    w->writeEndElement();
-
     // data
     if (m_dataItem) {
         w->writeStartElement(Tag::Data);
@@ -323,11 +318,6 @@ void DatafileItem::readFrom(QXmlStreamReader* r)
             initNativeData()->readFrom(r);
             XML::gotoEndElementOfTag(r, tag);
 
-            // native data units
-        } else if (tag == Tag::NativeDataUnits) {
-            XML::readAttribute(r, XML::Attrib::value, &m_nativeDataUnits);
-            XML::gotoEndElementOfTag(r, tag);
-
         } else
             r->skipCurrentElement();
     }
diff --git a/GUI/Model/Device/DatafileItem.h b/GUI/Model/Device/DatafileItem.h
index e8291e15e66e38b250f0efaeb0bda3380f0888ab..99d47cdfda8ef299e7c5da54fec53041180eb4d9 100644
--- a/GUI/Model/Device/DatafileItem.h
+++ b/GUI/Model/Device/DatafileItem.h
@@ -103,7 +103,6 @@ private:
 
     QString m_instrumentId;
     QString m_name;
-    QString m_nativeDataUnits = "bin";
     QString m_presentationType;
 
     // DataItem can be `Data2DItem` and `Data1DItem` (default `Data2DItem`).