diff --git a/unsupported/Eigen/KroneckerProduct b/unsupported/Eigen/KroneckerProduct
index 796e386ad..baddc3837 100644
--- a/unsupported/Eigen/KroneckerProduct
+++ b/unsupported/Eigen/KroneckerProduct
@@ -2,6 +2,7 @@
 #define EIGEN_KRONECKER_PRODUCT_MODULE_H
 
 #include "../../Eigen/Core"
+#include "../../Eigen/SparseCore"
 
 #include "../../Eigen/src/Core/util/DisableStupidWarnings.h"
 
diff --git a/unsupported/Eigen/src/KroneckerProduct/KroneckerTensorProduct.h b/unsupported/Eigen/src/KroneckerProduct/KroneckerTensorProduct.h
index 5149566a9..5c2841dbd 100644
--- a/unsupported/Eigen/src/KroneckerProduct/KroneckerTensorProduct.h
+++ b/unsupported/Eigen/src/KroneckerProduct/KroneckerTensorProduct.h
@@ -60,12 +60,6 @@ class KroneckerProduct : public ReturnByValue<KroneckerProduct<Lhs,Rhs> >
       return m_A.coeff(i / m_A.size()) * m_B.coeff(i % m_A.size());
     }
 
-#ifndef EIGEN_PARSED_BY_DOXYGEN
-    struct Unusable {};
-    Unusable& coeffRef(Index) { return *reinterpret_cast<Unusable*>(this); }
-    Unusable& coeffRef(Index,Index) { return *reinterpret_cast<Unusable*>(this); }
-#endif
-
   private:
     typename Lhs::Nested m_A;
     typename Rhs::Nested m_B;