Previous research has documented cross-linguistic influence in L2 grammatical gender acquisition and use. However, it remains unclear what role previously learned languages play in gender assignment beyond L2. To address this question, we created a timed gender decision task with which we tested two groups of L1 Polish university students of Swedish as an additional language: 65 L2 English/L3 Swedish students, and 52 L2 English/L3 German/L4 Swedish students. Adopting a pseudo-longitudinal design, we tested individuals who had completed one, two, or three to four years of studies. Accuracy and response time data were submitted to Generalised Linear Models. The results show that L4 Swedish students did not outperform L3 Swedish students in terms of accuracy. However, L4 Swedish students assigned gender to nouns faster than L3 Swedish students, but only after one year of studies. The response time advantage of L4S students was attributed to the surface transfer of the German gender values into Swedish. Apart from the specific effect of German, the results point to the robust effects of gender congruency with L1 Polish and the persistent tendency to overgeneralise uter gender.