diff --git a/docs/notifications.md b/docs/notifications.md
index a731855..b95e95e 100644
--- a/docs/notifications.md
+++ b/docs/notifications.md
@@ -2,13 +2,14 @@
 # Notifications
 
 Watchtower can send notifications when containers are updated. Notifications are sent via hooks in the logging system, [logrus](http://github.com/sirupsen/logrus).
-The types of notifications to send are passed via the space-separated option `--notifications` (or corresponding environment variable `WATCHTOWER_NOTIFICATIONS`), which has the following valid values:
+The types of notifications to send are set by passing a comma-separated list of values to the `--notifications` option (or corresponding environment variable `WATCHTOWER_NOTIFICATIONS`), which has the following valid values:
 
 - `email` to send notifications via e-mail
 - `slack` to send notifications through a Slack webhook
 - `msteams` to send notifications via MSTeams webhook
 - `gotify` to send notifications via Gotify
 
+> There is currently a [bug](https://github.com/spf13/viper/issues/380) in Viper, which prevents comma-separated slices to be used when using the environment variable. A workaround is available where we instead put quotes around the environment variable value and replace the commas with spaces, as `WATCHTOWER_NOTIFICATIONS="slack msteams"`
 
 > If you're a `docker-compose` user, make sure to specify environment variables' values in your `.yml` file without double quotes (`"`). 
 >