diff --git a/README.md b/README.md
index 3fa163d..efd1d6e 100644
--- a/README.md
+++ b/README.md
@@ -23,7 +23,7 @@ Following roles have been defined for making a server configuration easy:
 - **misc** contains some required but small roles
   - **backup_files** configures auto backup for a given directory
   - **deb_unstable** enables Debian unstable on low priority
-  - **docker** installs *Docker*
+  - **docker** installs *Docker* (from official Docker repository)
   - **handlers** contains some handlers used by other roles
   - **ip_discover** configures a server to automatically discover its ip addresses to a supported service
   - **system_user** creates a system user