diff --git a/Eigen/src/IterativeLinearSolvers/ConjugateGradient.h b/Eigen/src/IterativeLinearSolvers/ConjugateGradient.h
index 5d8c6b433..c3ca0ad54 100644
--- a/Eigen/src/IterativeLinearSolvers/ConjugateGradient.h
+++ b/Eigen/src/IterativeLinearSolvers/ConjugateGradient.h
@@ -29,8 +29,6 @@ void conjugate_gradient(const MatrixType& mat, const Rhs& rhs, Dest& x,
                         const Preconditioner& precond, Index& iters,
                         typename Dest::RealScalar& tol_error)
 {
-  using std::sqrt;
-  using std::abs;
   typedef typename Dest::RealScalar RealScalar;
   typedef typename Dest::Scalar Scalar;
   typedef Matrix<Scalar,Dynamic,1> VectorType;
@@ -56,7 +54,7 @@ void conjugate_gradient(const MatrixType& mat, const Rhs& rhs, Dest& x,
   if (residualNorm2 < threshold)
   {
     iters = 0;
-    tol_error = sqrt(residualNorm2 / rhsNorm2);
+    tol_error = numext::sqrt(residualNorm2 / rhsNorm2);
     return;
   }
 
@@ -86,7 +84,7 @@ void conjugate_gradient(const MatrixType& mat, const Rhs& rhs, Dest& x,
     p = z + beta * p;                           // update search direction
     i++;
   }
-  tol_error = sqrt(residualNorm2 / rhsNorm2);
+  tol_error = numext::sqrt(residualNorm2 / rhsNorm2);
   iters = i;
 }
 
diff --git a/test/vectorization_logic.cpp b/test/vectorization_logic.cpp
index f5c86afd3..b5464992e 100644
--- a/test/vectorization_logic.cpp
+++ b/test/vectorization_logic.cpp
@@ -279,10 +279,10 @@ struct vectorization_logic_half
     // which causes many of these tests to fail since they don't vectorize if
     // EIGEN_UNALIGNED_VECTORIZE is 0 (the matrix is assumed unaligned).
     // Adjust the matrix sizes to account for these alignment issues.
-    constexpr int PacketBytes = sizeof(Scalar)*PacketSize;
-    constexpr int MinVSize = EIGEN_UNALIGNED_VECTORIZE ? PacketSize
+    enum { PacketBytes = sizeof(Scalar)*PacketSize };
+    enum { MinVSize = EIGEN_UNALIGNED_VECTORIZE ? PacketSize
                              : PacketBytes >= EIGEN_MIN_ALIGN_BYTES ? PacketSize
-                             : (EIGEN_MIN_ALIGN_BYTES + sizeof(Scalar) - 1) / sizeof(Scalar);
+                             : (EIGEN_MIN_ALIGN_BYTES + sizeof(Scalar) - 1) / sizeof(Scalar) };
     
     typedef Matrix<Scalar,MinVSize,1> Vector1;
     typedef Matrix<Scalar,MinVSize,MinVSize> Matrix11;