A plate heat exchanger includes a plurality of heat transfer plates stacked on top of each other, wherein gaskets are positioned between adjacent heat transfer plates, wherein each gasket is arranged in a gasket groove formed in a heat transfer plate and a bottom part of the gasket groove defines a base level, wherein the gasket groove comprises a reinforcing pattern having a first recess at a first recess level and extending in a lengthwise direction of the gasket groove. The reinforcing pattern comprises a second recess at a second recess level extending in lengthwise direction of the gasket groove.