Adenosine diphosphate ribose (ADPr) can be linked to proteins by ADPr-transferases, which use β-NAD+ as a substrate to form an α-glycosidic bond while displacing nicotinamide. To study the localization and interactions of ADP-ribosylated proteins within cells, or to conduct pulldown-enrichment experiments from cell lysates to identify interacting proteins, it is important to stabilize this cleavable bond to protect it from degradation by cellular enzymes. Here, we describe the synthesis of a stable, non-hydrolysable triazole linkage via copper(I) catalyzed azide-alkyne cycloaddition (CuAAC) between 1″-α-azido-ADPribose and N-terminally biotinylated SUMO21–92 bearing a propargyl glycine substitution on the His17 position.