diff --git a/theme/main.html b/theme/main.html
index eea4e66270b02bd7c5f70920e569f3f650d55fb4..e08aea308dc22a673e893b8d92c875d0b6fcf281 100644
--- a/theme/main.html
+++ b/theme/main.html
@@ -27,7 +27,7 @@
     binderOptions: {
       repoProvider: "git",
       repo: "https://gitlab.kwant-project.org/solidstate/lectures",
-      ref: "e6c970126f4e819e4a3eb717a86ba9fb523d20bf",
+      ref: "master",
     },
     requestKernel: true,
     kernelOptions: {