The invention relates to the use of thermoplastic moulding compounds comprising: A) 30 - 99 wt.% of a thermoplastic polyamide, B) 0.01 - 10 wt.% of an organic isocyanate or diisocyanate or mixtures thereof, C) 0 - 60 wt.% additional additives, the total weight percentage A) - C) being 100 %. The invention also relates to the production of moulded bodies of any type with improved haze (measured according to ASTM D1003) and/or improved clarity (measured according to ASTM D1003) and/or increased laser transparency (measured at a wavelength of 1064 nm by means of a thermoelectric power measurement).