diff --git a/JSON/include/Poco/JSON/Object.h b/JSON/include/Poco/JSON/Object.h
index 0d6041fb0..f4be10fb2 100644
--- a/JSON/include/Poco/JSON/Object.h
+++ b/JSON/include/Poco/JSON/Object.h
@@ -320,7 +320,11 @@ inline const Dynamic::Var& Object::getValue(ValueMap::const_iterator& it) const
 
 inline const Dynamic::Var& Object::getValue(KeyPtrList::const_iterator& it) const
 {
-	return _values.at(**it);
+	ValueMap::const_iterator itv = _values.find(**it);
+	if (itv != _values.end())
+		return itv->second;
+	else
+		throw Poco::NotFoundException();
 }