A self-healing hydrophobic epoxy resin composition is provided. The self-healing epoxy resin composition comprises an epoxy resin component and a hardener component, the hardener component comprises at least 0.1 weight % of a modified epoxy resin hardener. The modified epoxy resin hardener is a reaction product of an amino modified oligomericsiloxane and a carboxylic acid anhydride. A process for preparing the modified epoxy resin hardener is also disclosed.