diff --git a/beets/util/inspect.py b/beets/util/inspect.py
index d114cfba2..4090030f1 100644
--- a/beets/util/inspect.py
+++ b/beets/util/inspect.py
@@ -21,12 +21,13 @@ from collections import namedtuple
 from six import PY2
 
 
+ArgSpec = namedtuple('ArgSpec', 'args varargs keywords defaults')
+
+
 def getargspec(func):
     if PY2:
         return inspect.getargspec(func)
 
-    ArgSpec = namedtuple('ArgSpec', 'args varargs keywords defaults')
-
     sig = inspect.signature(func)
     args = [
         p.name for p in sig.parameters.values()