diff --git a/setup.py b/setup.py
index f14de5223..fa744ad02 100644
--- a/setup.py
+++ b/setup.py
@@ -3,6 +3,9 @@
 import subprocess
 
 from pip._internal import main as pipmain
+if not callable(pipmain):
+    from pip._internal.main import main as pipmain
+
 import sys
 import warnings
 import os