diff --git a/homeassistant/components/notify/slack.py b/homeassistant/components/notify/slack.py
index 7c0a2b4d118..48f80138073 100644
--- a/homeassistant/components/notify/slack.py
+++ b/homeassistant/components/notify/slack.py
@@ -14,7 +14,7 @@ from homeassistant.const import (
     CONF_API_KEY, CONF_USERNAME, CONF_ICON)
 import homeassistant.helpers.config_validation as cv
 
-REQUIREMENTS = ['slacker==0.9.25']
+REQUIREMENTS = ['slacker==0.9.28']
 
 _LOGGER = logging.getLogger(__name__)
 
diff --git a/requirements_all.txt b/requirements_all.txt
index 44c60f30d48..76b41fec1be 100644
--- a/requirements_all.txt
+++ b/requirements_all.txt
@@ -441,7 +441,7 @@ scsgate==0.1.0
 sendgrid==3.4.0
 
 # homeassistant.components.notify.slack
-slacker==0.9.25
+slacker==0.9.28
 
 # homeassistant.components.notify.xmpp
 sleekxmpp==1.3.1