diff --git a/plugins/prosody/prosody_ b/plugins/prosody/prosody_
index d088572b..92340439 100644
--- a/plugins/prosody/prosody_
+++ b/plugins/prosody/prosody_
@@ -166,7 +166,7 @@ def main():
                     if mode == "config":
                         print "%s.label %s" % (munin_var, vhost)
                     else:
-                        accounts = len([listfiles(account_dir)])
+                        accounts = len(list(listfiles(account_dir)))
                         print "%s.value %s" % (munin_var, accounts)
 
 def listdirs(folder):