diff --git a/requirements_dev.txt b/requirements_dev.txt
index 2a5332b..b7ef554 100644
--- a/requirements_dev.txt
+++ b/requirements_dev.txt
@@ -30,7 +30,7 @@ pycparser==2.17 # via cffi
 pyflakes==1.5.0 # via flake8
 Pygments==2.2.0           # via sphinx
 pytest==3.0.6
-pytz==2017.2 # via babel
+pytz==2017.3 # via babel
 PyYAML==3.12              # via watchdog
 six==1.10.0               # via cryptography, sphinx
 snowballstemmer==1.2.1    # via sphinx