diff --git a/.travis.yml b/.travis.yml
index 06fa8a3..0708c24 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -19,9 +19,9 @@ env:
     - TOX_SUFFIX="httplib2"
     - TOX_SUFFIX="boto"
     - TOX_SUFFIX="boto3"
-    - TOX_SUFFIX="urllib317"
     - TOX_SUFFIX="urllib319"
     - TOX_SUFFIX="urllib3110"
+    - TOX_SUFFIX="urllib3121"
     - TOX_SUFFIX="tornado3"
     - TOX_SUFFIX="tornado4"
     - TOX_SUFFIX="aiohttp"
diff --git a/tox.ini b/tox.ini
index 4b51783..20afac6 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,5 +1,5 @@
 [tox]
-envlist = {py26,py27,py33,py34,py35,py36,pypy,pypy3}-{flakes,requests216,requests213,requests27,requests26,requests25,requests24,requests23,requests22,requests1,httplib2,urllib317,urllib319,urllib3110,tornado3,tornado4,boto,boto3,aiohttp}
+envlist = {py26,py27,py33,py34,py35,py36,pypy,pypy3}-{flakes,requests216,requests213,requests27,requests26,requests25,requests24,requests23,requests22,requests1,httplib2,urllib319,urllib3110,urllib3121,tornado3,tornado4,boto,boto3,aiohttp}
 
 [testenv:flakes]
 skipsdist = True
@@ -29,9 +29,9 @@ deps =
     requests23: requests==2.3.0
     requests22: requests==2.2.1
     httplib2: httplib2
-    urllib317: urllib3==1.7.1
     urllib319: urllib3==1.9.1
     urllib3110: urllib3==1.10.2
+    urllib3121: urllib3==1.21.1
     {py26,py27,py33,py34,py35,py36,pypy}-tornado3: tornado>=3,<4
     {py26,py27,py33,py34,py35,py36,pypy}-tornado4: tornado>=4,<5
     {py26,py27,py33,py34,py35,py36,pypy}-tornado3: pytest-tornado