diff --git a/tests/test-install.t b/tests/test-install.t
--- a/tests/test-install.t
+++ b/tests/test-install.t
@@ -236,6 +236,11 @@
 
 #endif
 
+#if py3
+  $ HGALLOWPYTHON3=1
+  $ export HGALLOWPYTHON3
+#endif
+
 #if virtualenv
 
 Verify that Mercurial is installable with pip. Note that this MUST be