diff --git a/src/calibre/ebooks/oeb/polish/stats.py b/src/calibre/ebooks/oeb/polish/stats.py
index 118fcdb98d..60b24a6c11 100644
--- a/src/calibre/ebooks/oeb/polish/stats.py
+++ b/src/calibre/ebooks/oeb/polish/stats.py
@@ -149,11 +149,9 @@ class Page(QWebPage):  # {{{
         self.mainFrame().addToJavaScriptWindowObject("py_bridge", self)
         self.evaljs(self.js)
         self.evaljs('''
-        py_bridge.__defineGetter__('value', function() {
-            return JSON.parse(this._pass_json_value);
-        });
-        py_bridge.__defineSetter__('value', function(val) {
-            this._pass_json_value = JSON.stringify(val);
+        Object.defineProperty(py_bridge, 'value', {
+               get : function() { return JSON.parse(this._pass_json_value); },
+               set : function(val) { this._pass_json_value = JSON.stringify(val); }
         });
         ''')
 # }}}
diff --git a/src/calibre/ebooks/pdf/render/from_html.py b/src/calibre/ebooks/pdf/render/from_html.py
index d931703420..ba6d605c27 100644
--- a/src/calibre/ebooks/pdf/render/from_html.py
+++ b/src/calibre/ebooks/pdf/render/from_html.py
@@ -345,11 +345,9 @@ class PDFWriter(QObject):
         self.load_mathjax()
 
         evaljs('''
-        py_bridge.__defineGetter__('value', function() {
-            return JSON.parse(this._pass_json_value);
-        });
-        py_bridge.__defineSetter__('value', function(val) {
-            this._pass_json_value = JSON.stringify(val);
+        Object.defineProperty(py_bridge, 'value', {
+               get : function() { return JSON.parse(this._pass_json_value); },
+               set : function(val) { this._pass_json_value = JSON.stringify(val); }
         });
 
         document.body.style.backgroundColor = "white";
diff --git a/src/calibre/ebooks/pdf/writer.py b/src/calibre/ebooks/pdf/writer.py
index 9ba9caf7f1..664f9350b3 100644
--- a/src/calibre/ebooks/pdf/writer.py
+++ b/src/calibre/ebooks/pdf/writer.py
@@ -250,11 +250,9 @@ class PDFWriter(QObject):  # {{{
         evaljs = self.view.page().mainFrame().evaluateJavaScript
         evaljs(self.paged_js)
         evaljs('''
-        py_bridge.__defineGetter__('value', function() {
-            return JSON.parse(this._pass_json_value);
-        });
-        py_bridge.__defineSetter__('value', function(val) {
-            this._pass_json_value = JSON.stringify(val);
+        Object.defineProperty(py_bridge, 'value', {
+               get : function() { return JSON.parse(this._pass_json_value); },
+               set : function(val) { this._pass_json_value = JSON.stringify(val); }
         });
 
         document.body.style.backgroundColor = "white";
diff --git a/src/calibre/gui2/viewer/documentview.py b/src/calibre/gui2/viewer/documentview.py
index 65f21869f8..4480581ee2 100644
--- a/src/calibre/gui2/viewer/documentview.py
+++ b/src/calibre/gui2/viewer/documentview.py
@@ -180,12 +180,10 @@ class Document(QWebPage):  # {{{
     def add_window_objects(self):
         self.mainFrame().addToJavaScriptWindowObject("py_bridge", self)
         self.javascript('''
-                py_bridge.__defineGetter__('value', function() {
-                    return JSON.parse(this._pass_json_value);
-                });
-                py_bridge.__defineSetter__('value', function(val) {
-                    this._pass_json_value = JSON.stringify(val);
-                });
+        Object.defineProperty(py_bridge, 'value', {
+               get : function() { return JSON.parse(this._pass_json_value); },
+               set : function(val) { this._pass_json_value = JSON.stringify(val); }
+        });
         ''')
         self.loaded_javascript = False