diff --git a/README.md b/README.md
index 3a543e2..2e7aeac 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,6 @@
 ---
 projectpages: "https://gitlab.com/preserves/preserves"
-projecttree: "https://gitlab.com/preserves/preserves/tree/master"
+projecttree: "https://gitlab.com/preserves/preserves/tree/main"
 title: "Preserves: an Expressive Data Language"
 no_site_title: true
 ---