diff --git a/lib/awesome_nested_set/model/movable.rb b/lib/awesome_nested_set/model/movable.rb
index accd3890..1da5daf0 100644
--- a/lib/awesome_nested_set/model/movable.rb
+++ b/lib/awesome_nested_set/model/movable.rb
@@ -46,7 +46,17 @@ def move_to_child_with_index(node, index)
             elsif node.children.count == index
               move_to_right_of(node.children.last)
             else
-              move_to_left_of(node.children[index])
+              my_position = node.children.index(self)
+              if my_position && my_position < index
+                # e.g. if self is at position 0 and we want to move self to position 1 then self
+                # needs to move to the *right* of the node at position 1. That's because the node
+                # that is currently at position 1 will be at position 0 after the move completes.
+                move_to_right_of(node.children[index])
+              elsif my_position && my_position == index
+                # do nothing. already there.
+              else
+                move_to_left_of(node.children[index])
+              end
             end
           end
 
diff --git a/spec/awesome_nested_set_spec.rb b/spec/awesome_nested_set_spec.rb
index 67e63d26..c1d93b1c 100644
--- a/spec/awesome_nested_set_spec.rb
+++ b/spec/awesome_nested_set_spec.rb
@@ -539,6 +539,23 @@
       categories(:child_2).right.should == 7
     end
 
+    it "move downward within current parent" do
+      categories(:child_1).move_to_child_with_index(categories(:top_level), 1)
+      categories(:child_1).parent_id.should == categories(:top_level).id
+      categories(:child_1).left.should == 6
+      categories(:child_1).right.should == 7
+      categories(:child_2).reload
+      categories(:child_2).parent_id.should == categories(:top_level).id
+      categories(:child_2).left.should == 2
+      categories(:child_2).right.should == 5
+    end
+
+    it "move to the same position within current parent" do
+      categories(:child_1).move_to_child_with_index(categories(:top_level), 0)
+      categories(:child_1).parent_id.should == categories(:top_level).id
+      categories(:child_1).left.should == 2
+      categories(:child_1).right.should == 3
+    end
   end
 
   it "move_to_child_of_appends_to_end" do