diff --git a/Eigen/src/Cholesky/LDLT.h b/Eigen/src/Cholesky/LDLT.h
index 6a2d2994b..94b679ede 100644
--- a/Eigen/src/Cholesky/LDLT.h
+++ b/Eigen/src/Cholesky/LDLT.h
@@ -354,6 +354,7 @@ template<> struct ldlt_inplace<Lower>
   template<typename MatrixType, typename WDerived>
   static bool updateInPlace(MatrixType& mat, MatrixBase<WDerived>& w, typename MatrixType::RealScalar sigma=1)
   {
+    using internal::isfinite;
     typedef typename MatrixType::Scalar Scalar;
     typedef typename MatrixType::RealScalar RealScalar;
     typedef typename MatrixType::Index Index;
@@ -367,7 +368,7 @@ template<> struct ldlt_inplace<Lower>
     for (Index j = 0; j < size; j++)
     {
       // Check for termination due to an original decomposition of low-rank
-      if (!std::isfinite(alpha))
+      if (!isfinite(alpha))
         break;
 
       // Update the diagonal terms
diff --git a/Eigen/src/Core/MathFunctions.h b/Eigen/src/Core/MathFunctions.h
index 3680be4a0..971019f06 100644
--- a/Eigen/src/Core/MathFunctions.h
+++ b/Eigen/src/Core/MathFunctions.h
@@ -837,6 +837,17 @@ template<> struct scalar_fuzzy_impl<bool>
   
 };
 
+/****************************************************************************
+* Special functions                                                          *
+****************************************************************************/
+
+// std::isfinite is non standard, so let's define our own version,
+// even though it is not very efficient.
+template<typename T> bool isfinite(const T& x)
+{
+  return x<NumTraits<T>::highest() && x>NumTraits<T>::lowest();
+}
+
 } // end namespace internal
 
 #endif // EIGEN_MATHFUNCTIONS_H