diff --git a/Eigen/src/SparseCore/MappedSparseMatrix.h b/Eigen/src/SparseCore/MappedSparseMatrix.h
index 87aab8fed..2907e7129 100644
--- a/Eigen/src/SparseCore/MappedSparseMatrix.h
+++ b/Eigen/src/SparseCore/MappedSparseMatrix.h
@@ -111,6 +111,7 @@ class MappedSparseMatrix
     }
 
     class InnerIterator;
+    class ReverseInnerIterator;
 
     /** \returns the number of non zero coefficients */
     inline Index nonZeros() const  { return m_nnz; }
@@ -136,12 +137,6 @@ class MappedSparseMatrix<Scalar,_Flags,_Index>::InnerIterator
         m_end(mat.outerIndexPtr()[outer+1])
     {}
 
-    template<unsigned int Added, unsigned int Removed>
-    InnerIterator(const Flagged<MappedSparseMatrix,Added,Removed>& mat, Index outer)
-      : m_matrix(mat._expression()), m_id(m_matrix.outerIndexPtr()[outer]),
-        m_start(m_id), m_end(m_matrix.outerIndexPtr()[outer+1])
-    {}
-
     inline InnerIterator& operator++() { m_id++; return *this; }
 
     inline Scalar value() const { return m_matrix.valuePtr()[m_id]; }
@@ -161,4 +156,35 @@ class MappedSparseMatrix<Scalar,_Flags,_Index>::InnerIterator
     const Index m_end;
 };
 
+template<typename Scalar, int _Flags, typename _Index>
+class MappedSparseMatrix<Scalar,_Flags,_Index>::ReverseInnerIterator
+{
+  public:
+    ReverseInnerIterator(const MappedSparseMatrix& mat, Index outer)
+      : m_matrix(mat),
+        m_outer(outer),
+        m_id(mat.outerIndexPtr()[outer+1]),
+        m_start(mat.outerIndexPtr()[outer]),
+        m_end(m_id)
+    {}
+
+    inline ReverseInnerIterator& operator--() { m_id--; return *this; }
+
+    inline Scalar value() const { return m_matrix.valuePtr()[m_id-1]; }
+    inline Scalar& valueRef() { return const_cast<Scalar&>(m_matrix.valuePtr()[m_id-1]); }
+
+    inline Index index() const { return m_matrix.innerIndexPtr()[m_id-1]; }
+    inline Index row() const { return IsRowMajor ? m_outer : index(); }
+    inline Index col() const { return IsRowMajor ? index() : m_outer; }
+
+    inline operator bool() const { return (m_id <= m_end) && (m_id>m_start); }
+
+  protected:
+    const MappedSparseMatrix& m_matrix;
+    const Index m_outer;
+    Index m_id;
+    const Index m_start;
+    const Index m_end;
+};
+
 #endif // EIGEN_MAPPED_SPARSEMATRIX_H
diff --git a/test/sparse_solvers.cpp b/test/sparse_solvers.cpp
index 3d1140bd1..a3d79b0ea 100644
--- a/test/sparse_solvers.cpp
+++ b/test/sparse_solvers.cpp
@@ -74,6 +74,13 @@ template<typename Scalar> void sparse_solvers(int rows, int cols)
                      m2.template triangularView<Upper>().solve(vec3));
     VERIFY_IS_APPROX(refMat2.conjugate().template triangularView<Upper>().solve(vec2),
                      m2.conjugate().template triangularView<Upper>().solve(vec3));
+    {
+      SparseMatrix<Scalar> cm2(m2);
+      //Index rows, Index cols, Index nnz, Index* outerIndexPtr, Index* innerIndexPtr, Scalar* valuePtr
+      MappedSparseMatrix<Scalar> mm2(rows, cols, cm2.nonZeros(), cm2.outerIndexPtr(), cm2.innerIndexPtr(), cm2.valuePtr());
+      VERIFY_IS_APPROX(refMat2.conjugate().template triangularView<Upper>().solve(vec2),
+                       mm2.conjugate().template triangularView<Upper>().solve(vec3));
+    }
 
     // lower - transpose
     initSparse<Scalar>(density, refMat2, m2, ForceNonZeroDiag|MakeLowerTriangular, &zeroCoords, &nonzeroCoords);