Merge pull request #11248 from Finkes/patch-1

improve Debian installation instructions

docs/sources/installation/debian.md

@@ -59,7 +59,9 @@ which is officially supported by Docker.
         $ sudo apt-get update
         $ sudo apt-get install -t wheezy-backports linux-image-amd64
 
-2. Install Docker using the get.docker.com script:
+2. Restart your system. This is necessary for Debian to use your new kernel.
+
+3. Install Docker using the get.docker.com script:
  
     `curl -sSL https://get.docker.com/ | sh`