diff --git a/dronekit/__init__.py b/dronekit/__init__.py
index bc05a7098..09979c6ec 100644
--- a/dronekit/__init__.py
+++ b/dronekit/__init__.py
@@ -48,7 +48,10 @@
 import time
 
 import monotonic
-from past.builtins import basestring
+
+# Python 2 had a builtin `basestring`; Python 3 does not.
+if sys.version_info.major >= 3:
+    basestring = str
 
 from pymavlink import mavutil, mavwp
 from pymavlink.dialects.v10 import ardupilotmega