diff --git a/src/core/ga_base.decl.hpp b/src/core/ga_base.decl.hpp
index af66b959..cab29478 100644
--- a/src/core/ga_base.decl.hpp
+++ b/src/core/ga_base.decl.hpp
@@ -614,21 +614,6 @@ namespace gapp
         bool isValidEvaluatedPopulation(const Population<T>& pop) const;
         bool isValidUnevaluatedPopulation(const Population<T>& pop) const;
         bool fitnessMatrixIsSynced() const;
-
-
-        /* Make the protected members of GaInfo private. */
-        using GaInfo::fitness_matrix_;
-        using GaInfo::algorithm_;
-        using GaInfo::stop_condition_;
-        using GaInfo::metrics_;
-        using GaInfo::on_generation_end_;
-        using GaInfo::population_size_;
-        using GaInfo::max_gen_;
-        using GaInfo::num_objectives_;
-        using GaInfo::generation_cntr_;
-        using GaInfo::num_fitness_evals_;
-        using GaInfo::keep_all_optimal_sols_;
-        using GaInfo::use_default_algorithm_;
     };
 
 } // namespace gapp
diff --git a/src/core/ga_info.hpp b/src/core/ga_info.hpp
index f49a35c2..9f35c298 100644
--- a/src/core/ga_info.hpp
+++ b/src/core/ga_info.hpp
@@ -340,11 +340,14 @@ namespace gapp
         /** Destructor. */
         virtual ~GaInfo() noexcept;
 
-    protected:
+    private:
 
         GaInfo(GaInfo&&) noexcept;
         GaInfo& operator=(GaInfo&&) noexcept;
 
+        template<typename T>
+        friend class GA;
+
         FitnessMatrix fitness_matrix_;
 
         std::unique_ptr<algorithm::Algorithm> algorithm_;