diff --git a/bin/uglifyjs b/bin/uglifyjs
index 8cbb3cadd87..8f1587121e4 100755
--- a/bin/uglifyjs
+++ b/bin/uglifyjs
@@ -232,9 +232,12 @@ function run() {
                 var result = {
                     _class: "AST_" + value.TYPE
                 };
-                value.CTOR.PROPS.forEach(function(prop) {
-                    result[prop] = value[prop];
-                });
+                var ctor = value.CTOR;
+                do {
+                    ctor.SELF_PROPS.forEach(function(prop) {
+                        result[prop] = value[prop];
+                    });
+                } while (ctor = ctor.BASE);
                 return result;
             }
             return value;
diff --git a/lib/ast.js b/lib/ast.js
index 0918574d11c..4d8b1431ed0 100644
--- a/lib/ast.js
+++ b/lib/ast.js
@@ -47,31 +47,35 @@ function DEFNODE(type, props, methods, base) {
     if (arguments.length < 4) base = AST_Node;
     if (!props) props = [];
     else props = props.split(/\s+/);
-    var self_props = props;
-    if (base && base.PROPS)
-        props = props.concat(base.PROPS);
-    var code = "return function AST_" + type + "(props){ if (props) { ";
-    for (var i = props.length; --i >= 0;) {
-        code += "this." + props[i] + " = props." + props[i] + ";";
-    }
-    var proto = base && new base;
-    if (proto && proto.initialize || (methods && methods.initialize))
-        code += "this.initialize();";
-    code += "}}";
+    var code = "return function AST_" + type + "(props) {\
+        if (props) {\
+            var ctor = this.CTOR;\
+            do {\
+                var self_props = ctor.SELF_PROPS;\
+                for (var i = self_props.length; i;) {\
+                    var k = self_props[--i];\
+                    this[k] = props[k];\
+                }\
+            } while (ctor = ctor.BASE);\
+            if (this.initialize) {\
+                this.initialize();\
+            }\
+        }\
+    }";
     var ctor = new Function(code)();
+    var proto = base && new base;
     if (proto) {
         ctor.prototype = proto;
         ctor.BASE = base;
     }
     if (base) base.SUBCLASSES.push(ctor);
     ctor.prototype.CTOR = ctor;
-    ctor.PROPS = props || null;
-    ctor.SELF_PROPS = self_props;
+    ctor.SELF_PROPS = props;
     ctor.SUBCLASSES = [];
     if (type) {
         ctor.prototype.TYPE = ctor.TYPE = type;
     }
-    if (methods) for (i in methods) if (HOP(methods, i)) {
+    if (methods) for (var i in methods) if (HOP(methods, i)) {
         if (/^\$/.test(i)) {
             ctor[i.substr(1)] = methods[i];
         } else {