diff --git a/python/webpage.py b/python/webpage.py
index 484e74a3..a197cd02 100644
--- a/python/webpage.py
+++ b/python/webpage.py
@@ -269,7 +269,7 @@ class WebPage(QObject):
 
     @pyqtSlot(str, result='QVariant')
     def evaluate(self, code):
-        function = '(function(){%s}).call(this);' % code
+        function = '(%s)()' % code
         return self.m_mainFrame.evaluateJavaScript(function)
 
     @pyqtSlot(str, str, 'QVariantMap')
diff --git a/src/webpage.cpp b/src/webpage.cpp
index 499425ad..aa0da7fe 100644
--- a/src/webpage.cpp
+++ b/src/webpage.cpp
@@ -209,7 +209,7 @@ QVariantMap WebPage::paperSize() const
 
 QVariant WebPage::evaluate(const QString &code)
 {
-    QString function = "(function(){" + code + "}).call(this);";
+    QString function = "(" + code + ")()";
     return m_mainFrame->evaluateJavaScript(function);
 }