An adhesion test allowing for the realistic assessment of adhesion needs for PV modules has been developed. The difference is that the test is conducted in-situ during ageing experiments. Weights were attached to the backsheet of tested PV mini-modules in order to test stability of lamination and adhesion. All samples were tested at standard test conditions of module temperature of 85ºC and 85% relative humidity. It is shown that appropriately laminated samples were able to withstand the force of 20g/cm for 1000 hours.