# apt-get upgrade
Reading package lists... Done
Building dependency tree
Reading state information... Done
You might want to run ‘apt-get -f install’ to correct these.
The following packages have unmet dependencies.
 linux-signed-image-3.19.0-51-generic : Depends: linux-image-3.19.0-51-generic (= 3.19.0-51.58~14.04.1) but 3.19.0-51.57~14.04.1 is installed
E: Unmet dependencies. Try using -f.