diff --git a/Surface_mesher/doc_tex/Surface_mesher_ref/SurfaceMeshComplex_2InTriangulation_3.tex b/Surface_mesher/doc_tex/Surface_mesher_ref/SurfaceMeshComplex_2InTriangulation_3.tex
index 0a222b58bcf..0463b5df357 100644
--- a/Surface_mesher/doc_tex/Surface_mesher_ref/SurfaceMeshComplex_2InTriangulation_3.tex
+++ b/Surface_mesher/doc_tex/Surface_mesher_ref/SurfaceMeshComplex_2InTriangulation_3.tex
@@ -63,7 +63,8 @@ i.e. find its size, number of connected components, genus etc...
 \ccRefName\ provides the following types.
 
 \ccNestedType{Triangulation}{The type of the
-embedding 3D triangulation.}
+embedding 3D triangulation. Must be a model of
+\ccc{SurfaceMeshTriangulation_3}.}
 \ccGlue
 \ccTypedef{typedef Triangulation::Vertex_handle Vertex_handle;}{ The type of
 the embedding triangulation vertex handles.}