diff --git a/Modules/Core/Functor/include/otbVariadicAddFunctor.h b/Modules/Core/Functor/include/otbVariadicAddFunctor.h
index cc0030d21513864a1d9aeff0f278bb7f2888fbe5..1ab244af33ab630ad0ce1543f1790bf1862961c3 100644
--- a/Modules/Core/Functor/include/otbVariadicAddFunctor.h
+++ b/Modules/Core/Functor/include/otbVariadicAddFunctor.h
@@ -31,6 +31,7 @@ namespace Functor
 /**
  * \class VariadicAdd
  * \brief This functor adds any number of compile time scalar inputs 
+ * \ingroup OTBFunctor
  */
 template <typename TOut, typename ...TIns> struct VariadicAdd
 {
diff --git a/Modules/Core/Functor/include/otbVariadicConcatenateFunctor.h b/Modules/Core/Functor/include/otbVariadicConcatenateFunctor.h
index fca836ada498fdc57cba704e28098187f5e516d5..c4903141aad2ebc38cdd131f9d77d7bceea42741 100644
--- a/Modules/Core/Functor/include/otbVariadicConcatenateFunctor.h
+++ b/Modules/Core/Functor/include/otbVariadicConcatenateFunctor.h
@@ -80,6 +80,7 @@ template <typename v1, typename v2, typename ...vn> void concatenateVectors(v1 &
  * \class VariadicConcatenate
  * \brief This functor concatenates any number of input of scalar type
  * or VariableLengthVector.
+ * \ingroup OTBFunctor
  */
 template<typename TOut, typename ...TIns> struct VariadicConcatenate
 {