diff --git a/mcs.xml b/mcs.xml
index e5778b57..45edea97 100644
--- a/mcs.xml
+++ b/mcs.xml
@@ -9,7 +9,7 @@
 
   <project name="HOL" path="HOL4" revision="successful-decompile" />
   <project name="graph-refine" />
-  <project name="isabelle" revision="ts-2022" />
+  <project name="isabelle" revision="ts-2023" />
   <project name="l4v" revision="rt" />
   <project name="polyml" path="HOL4/polyml" revision="successful-decompile"/>
   <project name="seL4" revision="7a0a4438cb8414d6f5c51d0e18669c65bed1cded"/>