diff --git a/.travis.yml b/.travis.yml
index 9b40d5e18b6..5bf413f630a 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -16,10 +16,8 @@ services:
     - mysql
 env:
     global:
-        - CFLAGS=-O0
         - DATABASE_URL=mysql://root:@127.0.0.1:3306/kuma
         - DJANGO_SETTINGS_MODULE=kuma.settings.travis
-        - DEBIAN_FRONTEND=noninteractive
         - DOCKER_COMPOSE_VERSION=1.9.0
           # ES_VERSION must come before ES_DOWNLOAD_URL
         - ES_VERSION=2.4.5
diff --git a/scripts/docker-compose.travis.yml b/scripts/docker-compose.travis.yml
index b5b198115fe..cd0642337d9 100644
--- a/scripts/docker-compose.travis.yml
+++ b/scripts/docker-compose.travis.yml
@@ -6,8 +6,6 @@ services:
       dockerfile: Dockerfile-base
     environment:
       - DJANGO_SETTINGS_MODULE
-      - DEBIAN_FRONTEND
-      - CFLAGS
 
   web:
     <<: *worker
diff --git a/tox.ini b/tox.ini
index d2916fbfaf7..e550e1a2ad1 100644
--- a/tox.ini
+++ b/tox.ini
@@ -10,15 +10,11 @@ commands =
     make compilejsi18n collectstatic clean
     py.test --no-migrations --cov=kuma kuma
 setenv =
-    PYTHONPATH = .
-    CFLAGS = -O0
     # TODO: remove once http://bugzil.la/1127798 is fixed
     PYTHONHASHSEED = 0
 passenv =
-    DJANGO_SETTINGS_MODULE
-    DEBIAN_FRONTEND
-    CFLAGS
     DATABASE_URL
+    DJANGO_SETTINGS_MODULE
     PIPELINE_*
 
 [testenv:flake8]