diff --git a/tox.ini b/tox.ini
index dbe0079c4..3ca9570a2 100644
--- a/tox.ini
+++ b/tox.ini
@@ -40,6 +40,10 @@ commands =
     --testr-args='^(?!.*test.*coverage).*$'
 
 [testenv:venv]
+# NOTE(jaegerandi): this target does not use constraints because
+# upstream infra does not yet support it. Once that's fixed, we can
+# drop the install_command.
+install_command = pip install -U --force-reinstall {opts} {packages}
 commands = {posargs}
 
 [testenv:docs]