diff --git a/requirements_dev.txt b/requirements_dev.txt
index 3e622af..c6e1781 100644
--- a/requirements_dev.txt
+++ b/requirements_dev.txt
@@ -5,7 +5,7 @@ pylint==1.9.2
 pytest==3.6.1
 pytest-cov==2.5.1
 pytest-mock==1.10.0
-tox==3.0.0
+tox==3.23.1
 Sphinx==1.7.5
 capturer==2.4
 requests-mock==1.5.0