diff --git a/joss/paper.bib b/joss/paper.bib
index 927744d..5af3c2d 100644
--- a/joss/paper.bib
+++ b/joss/paper.bib
@@ -843,7 +843,7 @@ @article{lewinsohnStatedependentEvolutionaryModels2023a
   pages = {581--596},
   publisher = {Nature Publishing Group},
   issn = {2397-334X},
-  doi = {10.1038/s41559-023-02000-4
+  doi = {10.1038/s41559-023-02000-4},
 }
 @article{Scott2018,
   title = {Inferring Tumour Proliferative Organisation from Phylogenetic Tree Measures in a Computational Model},