diff --git a/Eigen/src/Core/util/Memory.h b/Eigen/src/Core/util/Memory.h
index a54ccaedc..bacf236fb 100644
--- a/Eigen/src/Core/util/Memory.h
+++ b/Eigen/src/Core/util/Memory.h
@@ -523,9 +523,8 @@ template<typename T, bool Align> inline void conditional_aligned_delete_auto(T *
 template<typename Scalar, typename Index>
 inline Index first_aligned(const Scalar* array, Index size)
 {
-  enum { PacketSize = packet_traits<Scalar>::size,
-         PacketAlignedMask = PacketSize-1
-  };
+  static const Index PacketSize = packet_traits<Scalar>::size;
+  static const Index PacketAlignedMask = PacketSize-1;
 
   if(PacketSize==1)
   {