diff --git a/.travis.yml b/.travis.yml
index 4c63c98..0939953 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -2,6 +2,6 @@ language: python
 python:
   - "2.7"
 install:
-  - tox
+  - pip install tox
 script:
   - tox
diff --git a/jsonschema/_version.py b/jsonschema/_version.py
index 09485ee..2e07cd4 100644
--- a/jsonschema/_version.py
+++ b/jsonschema/_version.py
@@ -1,5 +1,5 @@
 
 # This file is automatically generated by setup.py.
-__version__ = '2.3.0.post139'
-__sha__ = 'g60fcbbf'
-__revision__ = 'g60fcbbf'
+__version__ = '2.3.0.post140'
+__sha__ = 'g839e656'
+__revision__ = 'g839e656'
diff --git a/version.txt b/version.txt
index d3b1894..a3c03d9 100644
--- a/version.txt
+++ b/version.txt
@@ -1 +1 @@
-v2.3.0-139-g60fcbbf
\ No newline at end of file
+v2.3.0-140-g839e656
\ No newline at end of file