diff --git a/doc/texinfo/gmsh.texi b/doc/texinfo/gmsh.texi
index 749c7173529e16b9470a9229a057c04939165f85..2927c9159c73421a36d8f944abfe8cd001f2d865 100644
--- a/doc/texinfo/gmsh.texi
+++ b/doc/texinfo/gmsh.texi
@@ -2431,6 +2431,11 @@ the X, Y and Z components of the translation vector.
 (Not a transformation per-se.) Returns the boundary of the elementary
 entities in @var{transform-list}.
 
+@item CombinedBoundary @{ @var{transform-list} @}
+(Not a transformation per-se.) Returns the boundary of the elementary
+entities, combined as if a single entity, in
+@var{transform-list}. Useful to compute the boundary of a complex part.
+
 @c @item Intersect Line @{ @var{expression-list} @} Surface @{ @var{expression} @}
 @c (Not a transformation per-se.) Returns the intersections of the lines
 @c given in @var{expression-list} with the specified surface.