diff --git a/tox.ini b/tox.ini
index 92cb54686..f4e892e46 100644
--- a/tox.ini
+++ b/tox.ini
@@ -26,6 +26,7 @@ skip_install = True
 passenv =
     CI
     CONTAINER_*
+    DISPLAY
     DOCKER_*
     GITHUB_*
     HOME