diff --git a/tox.ini b/tox.ini
index 3b764abc..b03ca424 100644
--- a/tox.ini
+++ b/tox.ini
@@ -2,11 +2,11 @@
 envlist =
     flake8
     py26-{tw121,tw132,tw154,asyncio}
-    py27-{tw121,tw132,tw154,twtrunk,asyncio}
-    pypy-{tw121,tw132,tw154,twtrunk,asyncio}
-    py33-{tw154,twtrunk,asyncio}
-    py34-{tw154,twtrunk,asyncio}
-    py35-{tw154,twtrunk,asyncio}
+    py27-{tw121,tw132,tw155,twtrunk,asyncio}
+    pypy-{tw121,tw132,tw155,twtrunk,asyncio}
+    py33-{tw155,twtrunk,asyncio}
+    py34-{tw155,twtrunk,asyncio}
+    py35-{tw155,twtrunk,asyncio}
 
 
 [flake8]
@@ -25,8 +25,9 @@ deps =
     tw121: twisted==12.1.0
     tw132: twisted==13.2.0
     tw154: twisted==15.4.0
+    tw155: twisted==15.5.0
     twtrunk: https://github.com/twisted/twisted/archive/trunk.zip
-    {tw121,tw132,tw154,twtrunk}: pytest-twisted
+    {tw121,tw132,tw155,twtrunk}: pytest-twisted
 
     ; asyncio dependencies
     py26-asyncio: trollius>=2.0
@@ -41,14 +42,14 @@ commands =
     python -V
     coverage --version
     asyncio: coverage run {envbindir}/py.test autobahn/
-    tw121,tw132,tw154,twtrunk: coverage run {envbindir}/trial autobahn
+    tw121,tw132,tw155,twtrunk: coverage run {envbindir}/trial autobahn
     coverage report
 
 whitelist_externals = sh
 
 setenv =
    asyncio: USE_ASYNCIO = 1
-   tw121,tw132,tw154,twtrunk: USE_TWISTED = 1
+   tw121,tw132,tw155,twtrunk: USE_TWISTED = 1
 
 
 [testenv:flake8]