diff --git a/biolink-model.yaml b/biolink-model.yaml
index 2a512c448c..07ef741de6 100644
--- a/biolink-model.yaml
+++ b/biolink-model.yaml
@@ -138,6 +138,8 @@ prefixes:
   # resolvable Base URI, but we point to a pair of sensible web documents
   STY: 'http://purl.bioontology.org/ontology/STY/'
   UMLSSG: 'https://lhncbc.nlm.nih.gov/semanticnetwork/download/sg_archive/SemGroups-v04.txt'
+  UniProtKB: 'http://purl.uniprot.org/uniprot/'
+  UNIPROT.ISOFORM: 'http://purl.uniprot.org/isoforms/'
   VANDF: 'https://www.nlm.nih.gov/research/umls/sourcereleasedocs/current/VANDF/'
   UO-PROPERTY: 'http://purl.obolibrary.org/obo/uo#'
   # The "Variation Modelling Collaboration" (VMC) is not (yet) a conventional namespace so we point to its Github repo