Qt lingust, Translation file broken when qsTrId contain <

For conveniance, i add arrow "<==" translation to later use unicode in .ts file. I add this text in a qml file using 

qsTrId(...) 

But after updating the ts file to add this text, the file can no longer be open with QtLingust displaying an error

sans_titre_fr_FR.ts:6:18: Unexpected '<'. 

4:<context>
5:    <name></name>
6:    <message id="<==">
7:        <location filename="main.qml" line="8"/>
8:        <source></source>
9:        <translation type="unfinished"></translation>
10:    </message>
11:</context> 

I forgot to add that it also break lupdate and lrelease forcing to manually correct the file.