diff --git a/Control/DataModelRoot/DataModelRoot/RootType.h b/Control/DataModelRoot/DataModelRoot/RootType.h
index 43769201b00ef71fff7df0a1202d49ac4ea35b1c..d9efb7cee061ffbf3950d7ccf3eefe8f63685311 100644
--- a/Control/DataModelRoot/DataModelRoot/RootType.h
+++ b/Control/DataModelRoot/DataModelRoot/RootType.h
@@ -87,9 +87,9 @@ public:
    Bool_t IsTransient() const;
 
    size_t FunctionParameterSize( Bool_t required = false ) const;
-   TMemberAdapter FunctionParameterAt( size_t nth ) const;
-   std::string FunctionParameterNameAt( size_t nth ) const;
-   std::string FunctionParameterDefaultAt( size_t nth ) const;
+   TMemberAdapter FunctionParameterAt( size_t nth );
+   std::string FunctionParameterNameAt( size_t nth );
+   std::string FunctionParameterDefaultAt( size_t nth );
 
    TReturnTypeAdapter   ReturnType() const;
    TScopeAdapter        DeclaringScope ATLAS_NOT_THREAD_SAFE () const;
diff --git a/Control/DataModelRoot/src/RootType.cxx b/Control/DataModelRoot/src/RootType.cxx
index 0a8f269458484bae7bb9ad11deab506384d01f1b..3787086f5486e7d0c44f95a46f46d2ba69481364 100644
--- a/Control/DataModelRoot/src/RootType.cxx
+++ b/Control/DataModelRoot/src/RootType.cxx
@@ -267,14 +267,14 @@ size_t TMemberAdapter::FunctionParameterSize( Bool_t required ) const
 }
 
 //____________________________________________________________________________
-TMemberAdapter TMemberAdapter::FunctionParameterAt( size_t nth ) const
+TMemberAdapter TMemberAdapter::FunctionParameterAt( size_t nth )
 {
 // get the type info of the function parameter at position nth
    return (TMethodArg*)((TFunction*)fMember)->GetListOfMethodArgs()->At( nth );
 }
 
 //____________________________________________________________________________
-std::string TMemberAdapter::FunctionParameterNameAt( size_t nth ) const
+std::string TMemberAdapter::FunctionParameterNameAt( size_t nth )
 {
 // get the formal name, if available, of the function parameter at position nth
    const char* name =
@@ -286,7 +286,7 @@ std::string TMemberAdapter::FunctionParameterNameAt( size_t nth ) const
 }
 
 //____________________________________________________________________________
-std::string TMemberAdapter::FunctionParameterDefaultAt( size_t nth ) const
+std::string TMemberAdapter::FunctionParameterDefaultAt( size_t nth )
 {
 // get the default value, if available, of the function parameter at position nth
    TMethodArg* arg = (TMethodArg*)((TFunction*)fMember)->GetListOfMethodArgs()->At( nth );