diff --git a/tox.ini b/tox.ini
index ea1423415..21dfd4604 100644
--- a/tox.ini
+++ b/tox.ini
@@ -14,15 +14,15 @@ envlist = modification,py{26,33,34,35,36},cover,lint
 # are detected, c.f. #1002
 commands =
     pip install -e acme[dev]
-    nosetests -v acme --processes=-1
+    nosetests -v acme
     pip install -e .[dev]
-    nosetests -v certbot --processes=-1 --process-timeout=100
+    nosetests -v certbot
     pip install -e certbot-apache
-    nosetests -v certbot_apache --processes=-1 --process-timeout=80
+    nosetests -v certbot_apache
     pip install -e certbot-nginx
-    nosetests -v certbot_nginx --processes=-1
+    nosetests -v certbot_nginx
     pip install -e letshelp-certbot
-    nosetests -v letshelp_certbot --processes=-1
+    nosetests -v letshelp_certbot
 
 setenv =
     PYTHONPATH = {toxinidir}
@@ -43,38 +43,38 @@ deps =
 [testenv:py33]
 commands =
     pip install -e acme[dev]
-    nosetests -v acme --processes=-1
+    nosetests -v acme
     pip install -e .[dev]
-    nosetests -v certbot --processes=-1 --process-timeout=100
+    nosetests -v certbot
     pip install -e certbot-apache
-    nosetests -v certbot_apache --processes=-1 --process-timeout=80
+    nosetests -v certbot_apache
 
 [testenv:py34]
 commands =
     pip install -e acme[dev]
-    nosetests -v acme --processes=-1
+    nosetests -v acme
     pip install -e .[dev]
-    nosetests -v certbot --processes=-1 --process-timeout=100
+    nosetests -v certbot
     pip install -e certbot-apache
-    nosetests -v certbot_apache --processes=-1 --process-timeout=80
+    nosetests -v certbot_apache
 
 [testenv:py35]
 commands =
     pip install -e acme[dev]
-    nosetests -v acme --processes=-1
+    nosetests -v acme
     pip install -e .[dev]
-    nosetests -v certbot --processes=-1 --process-timeout=100
+    nosetests -v certbot
     pip install -e certbot-apache
-    nosetests -v certbot_apache --processes=-1 --process-timeout=80
+    nosetests -v certbot_apache
 
 [testenv:py36]
 commands =
     pip install -e acme[dev]
-    nosetests -v acme --processes=-1
+    nosetests -v acme
     pip install -e .[dev]
-    nosetests -v certbot --processes=-1 --process-timeout=100
+    nosetests -v certbot
     pip install -e certbot-apache
-    nosetests -v certbot_apache --processes=-1 --process-timeout=80
+    nosetests -v certbot_apache
 
 [testenv:py27_install]
 basepython = python2.7