When using spring namespaces to configure compass, custom converters are not picked up. The reason for that is actually in the SchemConfigurationBuilder that the namespace handler uses under the hood. The bindConverters(...) method in the builder uses "DomUtils.getChildElementsByTagName(ele, "converter")" to retrieve all converters. This method by default matches the node name but the matching should be done on the local name, that is, it should use "DomUtils.getChildElementsByTagName(ele, "converter", true)" method instead.