Time for some love for Pathfinder. How about a feat that allows you to respond to an attack with you shield.
Shield Reposte (combat)
When people get close to your shiield, you know how to make them pay.
Prerequisite(s): Improved Shield Bash, Shield Proficiency
Benefit: Determine your AC with and without your shield. When an attack would fails to hit your normal AC, but would have hit your AC without your shield, you may as an immediate action, make a shield bash against the attacker.