diff --git a/test/redux.cpp b/test/redux.cpp
index 2dc4dcc45..104cd4cdd 100644
--- a/test/redux.cpp
+++ b/test/redux.cpp
@@ -52,6 +52,17 @@ template<typename MatrixType> void matrixRedux(const MatrixType& m)
   VERIFY_IS_APPROX(m1.prod(), p);
   VERIFY_IS_APPROX(m1.real().minCoeff(), ei_real(minc));
   VERIFY_IS_APPROX(m1.real().maxCoeff(), ei_real(maxc));
+
+  // test sclice vectorization assuming assign is ok
+  int r0 = ei_random<int>(0,rows-1);
+  int c0 = ei_random<int>(0,cols-1);
+  int r1 = ei_random<int>(r0+1,rows)-r0;
+  int c1 = ei_random<int>(c0+1,cols)-c0;
+  VERIFY_IS_APPROX(m1.block(r0,c0,r1,c1).sum(), m1.block(r0,c0,r1,c1).eval().sum());
+  VERIFY_IS_APPROX(m1.block(r0,c0,r1,c1).mean(), m1.block(r0,c0,r1,c1).eval().mean());
+  VERIFY_IS_APPROX(m1.block(r0,c0,r1,c1).prod(), m1.block(r0,c0,r1,c1).eval().prod());
+  VERIFY_IS_APPROX(m1.block(r0,c0,r1,c1).real().minCoeff(), m1.block(r0,c0,r1,c1).real().eval().minCoeff());
+  VERIFY_IS_APPROX(m1.block(r0,c0,r1,c1).real().maxCoeff(), m1.block(r0,c0,r1,c1).real().eval().maxCoeff());
 }
 
 template<typename VectorType> void vectorRedux(const VectorType& w)