1 files changed, 3 insertions, 0 deletions
diff --git a/.buildkite/scripts/test_old_deps.sh b/.buildkite/scripts/test_old_deps.sh
index 9905c4bc4f..28e6694b5d 100755
--- a/.buildkite/scripts/test_old_deps.sh
+++ b/.buildkite/scripts/test_old_deps.sh
@@ -10,4 +10,7 @@ apt-get install -y python3.5 python3.5-dev python3-pip libxml2-dev libxslt-dev x
 
 export LANG="C.UTF-8"
 
+# Prevent virtualenv from auto-updating pip to an incompatible version
+export VIRTUALENV_NO_DOWNLOAD=1
+
 exec tox -e py35-old,combine