--- a/tests/test-basic.t	Thu Jun 15 14:22:39 2017 -0400
+++ b/tests/test-basic.t	Tue Jun 20 09:45:02 2017 -0400
@@ -60,7 +60,7 @@
   > EOF
   $ hg up null
   0 files updated, 0 files merged, 1 files removed, 0 files unresolved
-  $ python ./update_to_rev0.py
+  $ $PYTHON ./update_to_rev0.py
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ hg identify -n
   0