Clearance of arrested nascent polypeptides resulting from ribosomal stalling is essential for proteostasis. Stalled endoplasmic reticulum (ER)-bound ribosomes are marked by ubiquitin-fold modifier 1 (UFM1) on the large ribosomal subunit protein RPL26, but the precise role of this modification in ribosome-associated quality control (RQC) remains poorly understood. Here, we define the interplay between the UFMylation machinery and the RQC in clearing arrested polypeptides upon ribosome stalling at