diff --git a/demo/binary_classification/mushroom.conf b/demo/binary_classification/mushroom.conf
index dbc832244..d364905f7 100644
--- a/demo/binary_classification/mushroom.conf
+++ b/demo/binary_classification/mushroom.conf
@@ -1,6 +1,6 @@
 # General Parameters, see comment for each definition
-# choose the tree booster, 0: tree, 1: linear
-booster_type = 0 
+# choose the booster, can be gbtree or gblinear
+booster = gbtree
 # choose logistic regression loss function for binary classification
 objective = binary:logistic
 
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"
diff --git a/demo/regression/machine.conf b/demo/regression/machine.conf
index 5142bcbcf..f5a5163a8 100644
--- a/demo/regression/machine.conf
+++ b/demo/regression/machine.conf
@@ -1,6 +1,6 @@
 # General Parameters, see comment for each definition
-# choose the tree booster, 0: tree, 1: linear
-booster_type = 0 
+# choose the tree booster, can also change to gblinear
+booster = gbtree
 # this is the only difference with classification, use reg:linear to do linear classification
 # when labels are in [0,1] we can also use reg:logistic
 objective = reg:linear