diff --git a/tests/validation/NEON/Gaussian5x5.cpp b/tests/validation/NEON/Gaussian5x5.cpp
index a553078..bb48961 100644
--- a/tests/validation/NEON/Gaussian5x5.cpp
+++ b/tests/validation/NEON/Gaussian5x5.cpp
@@ -54,6 +54,9 @@
 
 namespace
 {
+constexpr unsigned int filter_size = 5;              /** Size of the kernel/filter in number of elements. */
+constexpr BorderSize   border_size(filter_size / 2); /** Border size of the kernel/filter around its central element. */
+
 /** Compute Neon gaussian5x5 filter.
  *
  * @param[in] shape                 Shape of the input and output tensors.
@@ -109,7 +112,7 @@
 
     // Validate valid region
     const ValidRegion src_valid_region = shape_to_valid_region(shape);
-    const ValidRegion dst_valid_region = shape_to_valid_region(shape, border_mode == BorderMode::UNDEFINED, BorderSize(2));
+    const ValidRegion dst_valid_region = shape_to_valid_region(shape, border_mode == BorderMode::UNDEFINED, border_size);
     validate(src.info()->valid_region(), src_valid_region);
     validate(dst.info()->valid_region(), dst_valid_region);
 
@@ -143,7 +146,7 @@
     RawTensor ref_dst = Reference::compute_reference_gaussian5x5(shape, border_mode, border_value);
 
     // Validate output
-    validate(NEAccessor(dst), ref_dst, shape_to_valid_region(shape, border_mode == BorderMode::UNDEFINED, BorderSize(2)));
+    validate(NEAccessor(dst), ref_dst, shape_to_valid_region(shape, border_mode == BorderMode::UNDEFINED, border_size));
 }
 
 BOOST_TEST_DECORATOR(*boost::unit_test::label("nightly"))
@@ -160,7 +163,7 @@
     RawTensor ref_dst = Reference::compute_reference_gaussian5x5(shape, border_mode, border_value);
 
     // Validate output
-    validate(NEAccessor(dst), ref_dst, shape_to_valid_region(shape, border_mode == BorderMode::UNDEFINED, BorderSize(2)));
+    validate(NEAccessor(dst), ref_dst, shape_to_valid_region(shape, border_mode == BorderMode::UNDEFINED, border_size));
 }
 
 BOOST_AUTO_TEST_SUITE_END()