diff --git a/.travis.yml b/.travis.yml
index c126d99..8ff4ca0 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,4 +1,4 @@
 language: python
 python:
-  - "2.7"
+  - "3"
 script: python -m doctest README.md
diff --git a/README.md b/README.md
index ff90f8f..60dd015 100644
--- a/README.md
+++ b/README.md
@@ -38,7 +38,7 @@ The logic delegate can respond by setting the elevator to move up, move down, or
     >>> class Elevator(Elevator):
     ...     def __init__(self, logic_delegate, starting_floor=1):
     ...         self._current_floor = starting_floor
-    ...         print "%s..." % starting_floor,
+    ...         print(f"{starting_floor}...")
     ...         self._motor_direction = None
     ...         self._logic_delegate = logic_delegate
     ...         self._logic_delegate.callbacks = self.Callbacks(self)
@@ -71,7 +71,7 @@ The simulation runs in steps. Each time step consists of the elevator moving a s
     ... 
     ...        if delta:
     ...            self._current_floor = self._current_floor + delta
-    ...            print "%s..." % self._current_floor,
+    ...            print(f"{self._current_floor}...")
     ...            self._logic_delegate.on_floor_changed()
     ...        else:
     ...            self._logic_delegate.on_ready()
@@ -274,7 +274,7 @@ No amount of legal moves should compel the elevator to enter an illegal state. H
     >>> import random
     >>> e = Elevator(ElevatorLogic())
     1...
-    >>> try: print '-',  # doctest:+ELLIPSIS
+    >>> try: print('-')  # doctest:+ELLIPSIS
     ... finally:
     ...     for i in range(100000):  
     ...         r = random.randrange(6)
diff --git a/elevator.py b/elevator.py
index b44c167..dcb1b43 100644
--- a/elevator.py
+++ b/elevator.py
@@ -2,7 +2,7 @@
 DOWN = 2
 FLOOR_COUNT = 6
 
-class ElevatorLogic(object):
+class ElevatorLogic:
     """
     An incorrect implementation. Can you make it pass all the tests?