diff --git a/docs/03-declarative-layout.md b/docs/03-declarative-layout.md
index 0c608401..a25a34e1 100644
--- a/docs/03-declarative-layout.md
+++ b/docs/03-declarative-layout.md
@@ -227,11 +227,15 @@ caught by a Lua `metatable` (operator overload).
 
 Code:
 
-    -- "Monkeypatch" a new function to wibox.widget.textbox to add vicious
+    -- "Monkeypatch" a new function to 3 widget classes to add vicious
     -- extension support
-    function wibox.widget.textbox:vicious(args)
-        local f = unpack or table.unpack -- Lua 5.1 compat
-        vicious.register(w, f(args))
+    for _, wdg in ipairs {
+        wibox.widget.textbox , wibox.widget.progressbar, wibox.widget.graph
+    } do
+        function wdg:vicious(args)
+            local f = unpack or table.unpack -- Lua 5.1 compat
+            vicious.register(self, f(args))
+        end
     end
 
     s.mywibox : setup {