diff --git a/include/core/state_block/state_composite.h b/include/core/state_block/state_composite.h
index 0d83c63e531dcdf3f2d8918800d463e3f6a3d2c7..d0ddf4e7fc453212f345640f746cca212170f3b7 100644
--- a/include/core/state_block/state_composite.h
+++ b/include/core/state_block/state_composite.h
@@ -99,7 +99,7 @@ class MatrixComposite : public std::unordered_map < char, std::unordered_map < c
                         const std::list<int>& _row_sizes,
                         const StateStructure& _col_structure,
                         const std::list<int>& _col_sizes);
-//        MatrixComposite (const MatrixComposite& m);
+        MatrixComposite (const MatrixComposite& m);
         /**
          * \brief Construct from Eigen::VectorXd and structure
          *
@@ -358,12 +358,12 @@ inline StateBlockPtr wolf::StateBlockComposite::emplace(const char &_sb_type,
     return sb;
 }
 
-//inline MatrixComposite::MatrixComposite (const MatrixComposite& m)
-//        : unordered_map<char, unordered_map<char, MatrixXd> >(m), size_rows_(m.size_rows_), size_cols_(m.size_cols_)
-//{
-//}
-//
-//}
+inline MatrixComposite::MatrixComposite (const MatrixComposite& m)
+        : unordered_map<char, unordered_map<char, MatrixXd> >(m), size_rows_(m.size_rows_), size_cols_(m.size_cols_)
+{
+}
+
+}
 
 
 #endif /* STATE_BLOCK_STATE_COMPOSITE_H_ */