diff --git a/demo/rank/mq2008.conf b/demo/rank/mq2008.conf
index 65ad19b8e..90aadec4e 100644
--- a/demo/rank/mq2008.conf
+++ b/demo/rank/mq2008.conf
@@ -1,6 +1,4 @@
 # General Parameters, see comment for each definition
-# choose the tree booster, 0: tree, 1: linear
-booster_type = 0 
 
 # specify objective
 objective="rank:pairwise"