In ascomycete fungi, hyphal cells are separated by perforate septa, which allow cell-to-cell communication. To protect against extensive wound-induced damage, septal pores are sealed by peroxisome-derived Woronin bodies (WBs). The mechanism underpinning WB movement is unknown, but cytoplasmic bulk flow may “flush” WBs into the pore. However, some studies suggest a controlled and active mechanism of WB movement. Indeed, in the wheat pathogen Zymoseptoria tritici cellular ATP prevents WBs from pore sealing in unwounded cells. Thus, cells appear to exert active control over WB closure. Here, we summarize our current understanding of WB-based pore sealing in ascomycete fungi.