diff --git a/tox.ini b/tox.ini
index d4c4fec..952ea29 100644
--- a/tox.ini
+++ b/tox.ini
@@ -11,6 +11,10 @@ commands =
     coverage run -m pytest {posargs}
     coverage combine
     coverage report
+passenv =
+    CURL_CA_BUNDLE
+    REQUESTS_CA_BUNDLE
+    SSL_CERT_FILE
 
 [testenv:venv]
 deps =