diff --git a/lambda/requirements-deploy.txt b/lambda/requirements-deploy.txt
index ca68f59..ace7d83 100644
--- a/lambda/requirements-deploy.txt
+++ b/lambda/requirements-deploy.txt
@@ -1,3 +1,3 @@
 aws_kinesis_agg==1.1.2
 aws-xray-sdk==2.6.0
-python-dateutil==2.8.1
+python-dateutil==2.9.0.post0
diff --git a/lambda/requirements.txt b/lambda/requirements.txt
index 6c37eaf..ebc82ea 100644
--- a/lambda/requirements.txt
+++ b/lambda/requirements.txt
@@ -1,4 +1,4 @@
-python-dateutil==2.8.1
+python-dateutil==2.9.0.post0
 fluent-logger==0.9.5
 aws_kinesis_agg==1.1.2
 aws-xray-sdk==2.6.0