diff --git a/requirements.txt b/requirements.txt
index c5fe82a..00f2e3a 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,6 +1,6 @@
 connexion >= 2.6.0
 connexion[swagger-ui] >= 2.6.0
-python_dateutil == 2.6.0
+python_dateutil == 2.7.3
 setuptools >= 21.0.0
 swagger-ui-bundle >= 0.0.2
 peewee==3.15.0