diff --git a/Eigen/src/LU/FullPivLU.h b/Eigen/src/LU/FullPivLU.h
index 344ec89261..b4f4bc6ee7 100644
--- a/Eigen/src/LU/FullPivLU.h
+++ b/Eigen/src/LU/FullPivLU.h
@@ -18,6 +18,7 @@ template<typename _MatrixType> struct traits<FullPivLU<_MatrixType> >
 {
   typedef MatrixXpr XprKind;
   typedef SolverStorage StorageKind;
+  typedef int StorageIndex;
   enum { Flags = 0 };
 };
 
@@ -64,7 +65,6 @@ template<typename _MatrixType> class FullPivLU
     typedef SolverBase<FullPivLU> Base;
 
     EIGEN_GENERIC_PUBLIC_INTERFACE(FullPivLU)
-    // FIXME StorageIndex defined in EIGEN_GENERIC_PUBLIC_INTERFACE should be int
     enum {
       MaxRowsAtCompileTime = MatrixType::MaxRowsAtCompileTime,
       MaxColsAtCompileTime = MatrixType::MaxColsAtCompileTime
@@ -529,8 +529,8 @@ void FullPivLU<MatrixType>::computeInPlace()
       m_nonzero_pivots = k;
       for(Index i = k; i < size; ++i)
       {
-        m_rowsTranspositions.coeffRef(i) = i;
-        m_colsTranspositions.coeffRef(i) = i;
+        m_rowsTranspositions.coeffRef(i) = internal::convert_index<StorageIndex>(i);
+        m_colsTranspositions.coeffRef(i) = internal::convert_index<StorageIndex>(i);
       }
       break;
     }
@@ -541,8 +541,8 @@ void FullPivLU<MatrixType>::computeInPlace()
     // Now that we've found the pivot, we need to apply the row/col swaps to
     // bring it to the location (k,k).
 
-    m_rowsTranspositions.coeffRef(k) = row_of_biggest_in_corner;
-    m_colsTranspositions.coeffRef(k) = col_of_biggest_in_corner;
+    m_rowsTranspositions.coeffRef(k) = internal::convert_index<StorageIndex>(row_of_biggest_in_corner);
+    m_colsTranspositions.coeffRef(k) = internal::convert_index<StorageIndex>(col_of_biggest_in_corner);
     if(k != row_of_biggest_in_corner) {
       m_lu.row(k).swap(m_lu.row(row_of_biggest_in_corner));
       ++number_of_transpositions;
diff --git a/Eigen/src/LU/PartialPivLU.h b/Eigen/src/LU/PartialPivLU.h
index bfcd2c95bc..ecc0e748f3 100644
--- a/Eigen/src/LU/PartialPivLU.h
+++ b/Eigen/src/LU/PartialPivLU.h
@@ -19,6 +19,7 @@ template<typename _MatrixType> struct traits<PartialPivLU<_MatrixType> >
 {
   typedef MatrixXpr XprKind;
   typedef SolverStorage StorageKind;
+  typedef int StorageIndex;
   typedef traits<_MatrixType> BaseTraits;
   enum {
     Flags = BaseTraits::Flags & RowMajorBit,
@@ -80,7 +81,6 @@ template<typename _MatrixType> class PartialPivLU
     typedef _MatrixType MatrixType;
     typedef SolverBase<PartialPivLU> Base;
     EIGEN_GENERIC_PUBLIC_INTERFACE(PartialPivLU)
-    // FIXME StorageIndex defined in EIGEN_GENERIC_PUBLIC_INTERFACE should be int
     enum {
       MaxRowsAtCompileTime = MatrixType::MaxRowsAtCompileTime,
       MaxColsAtCompileTime = MatrixType::MaxColsAtCompileTime
diff --git a/test/lu.cpp b/test/lu.cpp
index 24bea784a3..46fd60555c 100644
--- a/test/lu.cpp
+++ b/test/lu.cpp
@@ -18,6 +18,8 @@ typename MatrixType::RealScalar matrix_l1_norm(const MatrixType& m) {
 
 template<typename MatrixType> void lu_non_invertible()
 {
+  STATIC_CHECK(( internal::is_same<typename FullPivLU<MatrixType>::StorageIndex,int>::value ));
+
   typedef typename MatrixType::RealScalar RealScalar;
   /* this test covers the following files:
      LU.h
@@ -191,6 +193,8 @@ template<typename MatrixType> void lu_partial_piv()
   m1.setRandom();
   PartialPivLU<MatrixType> plu(m1);
 
+  STATIC_CHECK(( internal::is_same<typename PartialPivLU<MatrixType>::StorageIndex,int>::value ));
+
   VERIFY_IS_APPROX(m1, plu.reconstructedMatrix());
 
   m3 = MatrixType::Random(size,size);