diff --git a/src/swayfocus.cr b/src/swayfocus.cr
index 06c900e..35a19c7 100644
--- a/src/swayfocus.cr
+++ b/src/swayfocus.cr
@@ -3,17 +3,32 @@ require "option_parser"
 
 version = "0.1"
 
+struct Nil
+    def includes? ( a : String)
+        false
+    end
+end
+
 class Window
-    JSON.mapping({
-        id: UInt32,
-        name: String,
-        wtype: {type: String, key: "type"},
-        app_id: {type: String, default: ""},
-        wclass: {type: String, key: "class", default: ""},
-        marks: {type: Array(String), default: [] of String},
-        nodes: {type: Array(Window), default: [] of Window},
-        focused: {type: Bool, default: false}
-    })
+    include JSON::Serializable
+
+    property id : UInt32 = 0
+
+    @[JSON::Field(emit_null: true)]
+    property name : String?
+
+    @[JSON::Field(key: "type")]
+    property wtype : String = ""
+
+    property app_id : String = ""
+
+    @[JSON::Field(key: "class")]
+    property wclass : String = ""
+
+    property marks : Array(String) = [] of String
+    property nodes : Array(Window) = [] of Window
+
+    property focused : Bool = false
 
     def clear_nodes
         @nodes = [] of Window
@@ -23,7 +38,7 @@ end
 def node_loop (root : Window)
     list = [] of Window
     root.nodes.each do |node|
-        if node.wtype == "con"
+        if node.wtype == "con" && !node.name.nil?
             list << node
         elsif !node.nodes.empty?
             list.concat node_loop node