diff --git a/herbert_core/utilities/classes/@hashable/eq.m b/herbert_core/utilities/classes/@hashable/eq.m
index 824220e567..fb982361c3 100644
--- a/herbert_core/utilities/classes/@hashable/eq.m
+++ b/herbert_core/utilities/classes/@hashable/eq.m
@@ -10,14 +10,18 @@
 %   obj2        Object on right-hand side
 %
 % See also equal_to_tol
-if ~isa(obj2,class(obj1))
-    iseq = false;
+
+% use generic overloadable methods to compare object's size and shape
+% as they are overloadable and may be different for children
+iseq = eq_to_tol_type_equal(obj1,obj2,'','');
+if ~iseq
     return;
 end
-if ~all(size(obj1)==size(obj2))
-    iseq = false;
+iseq  = eq_to_tol_shape_equal(obj1,obj2,'','',false);
+if ~iseq
     return;
 end
+
 for i=1:numel(obj1)
     [~,hash1] = build_hash(obj1(i));
     [~,hash2] = build_hash(obj2(i));
diff --git a/herbert_core/utilities/classes/@hashable/private/equal_to_tol_single_.m b/herbert_core/utilities/classes/@hashable/private/equal_to_tol_single_.m
index 10ee0ed6e8..387438dd7e 100644
--- a/herbert_core/utilities/classes/@hashable/private/equal_to_tol_single_.m
+++ b/herbert_core/utilities/classes/@hashable/private/equal_to_tol_single_.m
@@ -2,7 +2,8 @@
 % Compare single pair of hashable objects
 %
 % internal procedure used by equal_to_toll method to compare
-% single pair of hashable objects
+% single pair of hashable objects from possible array of such objects
+%
 % Input:
 % obj       -- first object to compare
 % other_obj -- second object to compare
diff --git a/herbert_core/utilities/classes/@serializable/ne.m b/herbert_core/utilities/classes/@serializable/ne.m
deleted file mode 100644
index 3366bfa760..0000000000
--- a/herbert_core/utilities/classes/@serializable/ne.m
+++ /dev/null
@@ -1,21 +0,0 @@
-function isne = ne (obj1, obj2)
-% Return a logical variable stating if two serializable objects are unequal or not
-%
-%   >> [iseq, mess] = ne (obj1, obj2)
-%
-% Input:
-% ------
-%   obj1        Object on left-hand side
-%
-%   obj2        Object on right-hand side
-%
-% Optional:
-%   p1, p2,...  Any set of parameters that the equal_to_tol function accepts
-%
-% See also equal_to_tol
-
-% TODO: can be done more efficiently as eq needs to check all
-% the fields and ne may return when found first non-equal field
-
-isne = ~eq(obj1,obj2);
-
diff --git a/herbert_core/utilities/classes/@serializable/serializable.m b/herbert_core/utilities/classes/@serializable/serializable.m
index f037074d5a..2e7960bbab 100644
--- a/herbert_core/utilities/classes/@serializable/serializable.m
+++ b/herbert_core/utilities/classes/@serializable/serializable.m
@@ -311,9 +311,12 @@
             iseq  = equal_to_tol(obj1,obj2);
         end
 
-        % Return logical variable stating if two serializable objects are
-        % unequal or not
-        isne = ne (obj1, obj2)
+        function  isne = ne (obj1, obj2)
+            % Return logical variable stating if two serializable objects are
+            % unequal or not. Should be optimized for comparing ne.            
+            isne  = ~equal_to_tol(obj1,obj2);
+        end
+        
 
         % Return logical variable stating if two serializable objects are equal
         % or not given some conditions of their equality.