diff --git a/scripts/eressea/xmlconf.lua b/scripts/eressea/xmlconf.lua
index 8ddd09539..9dfdca595 100644
--- a/scripts/eressea/xmlconf.lua
+++ b/scripts/eressea/xmlconf.lua
@@ -6,5 +6,5 @@ rules=''
 if config.rules then
     rules = config.rules .. '/'
 end
-read_xml(confdir .. rules .. 'config.xml', confdir .. rules .. 'catalog.xml')
-eressea.config.read(rules .. 'config.json', confdir)
+assert(0 == read_xml(confdir .. rules .. 'config.xml', confdir .. rules .. 'catalog.xml'), "could not load XML data, did you compile with LIBXML2 ?")
+assert(0 == eressea.config.read(rules .. 'config.json', confdir), "could not read JSON data")