diff --git a/.circleci/setup-virtualenv.sh b/.circleci/setup-virtualenv.sh
index ad5c7b5ac..feccbbf23 100755
--- a/.circleci/setup-virtualenv.sh
+++ b/.circleci/setup-virtualenv.sh
@@ -27,8 +27,11 @@ shift || :
 # Tell pip where it can find any existing wheels.
 export PIP_FIND_LINKS="file://${WHEELHOUSE_PATH}"
 
-# Don't let it look elsewhere.
-export PIP_NO_INDEX="1"
+# It is tempting to also set PIP_NO_INDEX=1 but (a) that will cause problems
+# between the time dependencies change and the images are re-built and (b) the
+# upcoming-deprecations job wants to install some dependencies from github and
+# it's awkward to get that done any earlier than the tox run.  So, we don't
+# set it.
 
 # Get everything else installed in it, too.
 "${BOOTSTRAP_VENV}"/bin/tox \