diff --git a/ngcp/utils.lua b/ngcp/utils.lua
index 31a19ca..1ffcb08 100644
--- a/ngcp/utils.lua
+++ b/ngcp/utils.lua
@@ -134,9 +134,14 @@ end
 
 -- GLOBAL
 Stack = {
-  __class__ = 'Stack'
+  __class__ = 'Stack',
+}
+Stack_MT = {
+  __index = Stack,
+  __tostring = function(t)
+    return table.tostring(Stack.list(t))
+  end
 }
-Stack_MT = { __index = Stack }
 
   -- Create a Table with stack functions
   function Stack:new()
diff --git a/tests/utils.lua b/tests/utils.lua
index 9d3e81b..97ecb38 100644
--- a/tests/utils.lua
+++ b/tests/utils.lua
@@ -88,6 +88,14 @@ TestStack = {}
         assertItemsEquals(l[1],{1,2,3})
         assertEquals(l[2],1)
     end
+
+    function TestStack:test_tostring()
+        s = Stack:new()
+        s:push(1)
+        assertEquals(tostring(s), "{1}")
+        s:push(2)
+        assertEquals(tostring(s), "{2,1}")
+    end
 -- class TestStack
 ---- Control test output:
 lu = LuaUnit