diff --git a/instrument/V20_4-tubes_90deg_Definition_v01.xml b/instrument/V20_4-tubes_90deg_Definition_v01.xml
index ce91af854d2ce9d0be397b916c3a7c078b222214..e60b04144da4c94225646941f05b950306304906 100644
--- a/instrument/V20_4-tubes_90deg_Definition_v01.xml
+++ b/instrument/V20_4-tubes_90deg_Definition_v01.xml
@@ -43,7 +43,7 @@ last-modified="2018-02-09 09:00:00">
       <location x="-0.070" />
       <location x="-0.035" />
       <location x="0.000" />
-      <location x="-0.035" />
+      <location x="0.035" />
     </component>
   </type>