diff --git a/robowaiter/behavior_tree/obtea/OptimalBTExpansionAlgorithm.py b/robowaiter/behavior_tree/obtea/OptimalBTExpansionAlgorithm.py
index 6ec11d5..7f0010f 100644
--- a/robowaiter/behavior_tree/obtea/OptimalBTExpansionAlgorithm.py
+++ b/robowaiter/behavior_tree/obtea/OptimalBTExpansionAlgorithm.py
@@ -185,10 +185,10 @@ class OptBTExpAlgorithm:
                 elif child.type == 'act':
                     self.ptml_string += 'act '+child.content.name+"\n"
             elif isinstance(child, ControlBT):
-                if parnode.type == '?':
+                if child.type == '?':
                     self.ptml_string += "selector{\n"
                     self.dfs_ptml(parnode=child)
-                elif parnode.type == '>':
+                elif child.type == '>':
                     self.ptml_string += "sequence{\n"
                     self.dfs_ptml( parnode=child)
                 self.ptml_string += '}\n'
diff --git a/sub_task.ptml b/sub_task.ptml
index b8bf4e1..adcea35 100644
--- a/sub_task.ptml
+++ b/sub_task.ptml
@@ -1,6 +1,6 @@
 selector{
 cond At(Coffee,Bar)
-selector{
+sequence{
 cond At(Robot,CoffeeMachine)
 act MakeCoffee()
 }