diff --git a/data/su/dataspecification_su.adoc b/data/su/dataspecification_su.adoc
index d08272c8..14ec85b2 100644
--- a/data/su/dataspecification_su.adoc
+++ b/data/su/dataspecification_su.adoc
@@ -1079,6 +1079,7 @@ The following constraints are added:
 * Each vector statistical unit cannot have more than one geometry with a type _referenceGeometry_,
 * Geometry descriptors with a _generalisedGeometry_ type have to be instances of _GeneralisedGeometryDescriptor_ class.
 * Vector statistical units with a reference geometry instance of _GM_MultiSurface_ must be instances of the specialised class _AreaStatisticalUnit_.
+* The reference geometry of an area statistical units should be a _GM_MultiSurface_.
 
 [NOTE]
 ====
@@ -2034,6 +2035,15 @@ a|
 !Stereotypes: !«voidable»
 !===
 
+a|
+*Constraint: AreaStatisticalUnitsGeometryConstraint*
+
+[cols=","]
+!===
+!Natural language: !The reference geometry of an area statistical units should be a _GM_MultiSurface_.
+!OCL: !
+!===
+
 |===
 
 ====== _Evolution_
diff --git a/data/su/media/image10.png b/data/su/media/image10.png
index a124b716..833d3c21 100644
Binary files a/data/su/media/image10.png and b/data/su/media/image10.png differ