diff --git a/Eigen/src/SparseCore/SparseMatrixBase.h b/Eigen/src/SparseCore/SparseMatrixBase.h
index ed7da6892..9d7b83577 100644
--- a/Eigen/src/SparseCore/SparseMatrixBase.h
+++ b/Eigen/src/SparseCore/SparseMatrixBase.h
@@ -372,7 +372,7 @@ template<typename Derived> class SparseMatrixBase : public EigenBase<Derived>
     const typename SparseDenseProductReturnType<Derived,OtherDerived>::Type
     operator*(const MatrixBase<OtherDerived> &other) const;
     
-     /** \returns an expression of P^-1 H P */
+     /** \returns an expression of P H P^-1 where H is the matrix represented by \c *this */
     SparseSymmetricPermutationProduct<Derived,Upper|Lower> twistedBy(const PermutationMatrix<Dynamic,Dynamic,Index>& perm) const
     {
       return SparseSymmetricPermutationProduct<Derived,Upper|Lower>(derived(), perm);
diff --git a/Eigen/src/SparseCore/SparseSelfAdjointView.h b/Eigen/src/SparseCore/SparseSelfAdjointView.h
index fc23b24d6..c925a894d 100644
--- a/Eigen/src/SparseCore/SparseSelfAdjointView.h
+++ b/Eigen/src/SparseCore/SparseSelfAdjointView.h
@@ -125,7 +125,7 @@ template<typename MatrixType, unsigned int UpLo> class SparseSelfAdjointView
       _dest = tmp;
     }
     
-    /** \returns an expression of P^-1 H P */
+    /** \returns an expression of P H P^-1 */
     SparseSymmetricPermutationProduct<_MatrixTypeNested,UpLo> twistedBy(const PermutationMatrix<Dynamic,Dynamic,Index>& perm) const
     {
       return SparseSymmetricPermutationProduct<_MatrixTypeNested,UpLo>(m_matrix, perm);