--- a/tdm/config.def
+++ b/tdm/config.def
@@ -2614,8 +2614,8 @@
 
 Key: UseTheme
 Type: bool
-Default: true
+Default: false
 User: greeter
-Instance: */true
+Instance: #*/true
 Comment: &
 Description:
  Whether the greeter should be themed.