Enveloped viruses hijack the protein production machinery of their host in order to proliferate and their replication/infectivity relies on the correct folding of their surface glycoproteins. This dependence on glycoprotein quality control for viral proliferation makes the host endoplasmic reticulum quality control (ERQC) mechanisms an attractive target for the development of hosttargeting antiviral agents, which may show broad-spectrum activity and a high genetic barrier to resistance. A key ERQC protein is α-glucosidase II (GluII), a heterodimeric enzyme bearing a catalytic α-subunit of the GH31 family and an accessory β-subunit that is necessary for full catalytic activity and for the localisation of the heterodimer in the ER. GluII mediates quality control of the folding of nascent glycoproteins by trimming glucose residues from its substrate glycan Glc1-2Man9GlcNAc2. Inhibition of GluII can be achieved using iminosugars which mimic the glucose residue of the native substrate, causing the build-up of misfolded protein in the ER and prevents the secretion of correctly folded glycoproteins. In the case of enveloped virus infection, this inhibits virion secretion or reduces infectivity of secreted virions and has been shown to elicit antiviral effect against a range of enveloped viruses in vitro and in vivo. Iminosugar inhibitors of GluII are effective, but have been associated with significant drugrelated adverse effects.