diff --git a/functions/billing/requirements.txt b/functions/billing/requirements.txt
index 3b0c903eb977..2041ad379319 100644
--- a/functions/billing/requirements.txt
+++ b/functions/billing/requirements.txt
@@ -1,4 +1,4 @@
-slackclient==2.8.2
+slackclient==2.9.0
 # [START functions_billing_limit_appengine_deps]
 google-api-python-client==1.11.0
 # [END functions_billing_limit_appengine_deps]
diff --git a/functions/slack/requirements.txt b/functions/slack/requirements.txt
index 7d2f235bd4dd..e504b4da41df 100644
--- a/functions/slack/requirements.txt
+++ b/functions/slack/requirements.txt
@@ -1,3 +1,3 @@
 google-api-python-client==1.11.0
 flask==1.1.2
-slackclient==2.8.2
+slackclient==2.9.0