diff --git a/default.xml b/default.xml
index d35f0b98..7dc57dd2 100644
--- a/default.xml
+++ b/default.xml
@@ -5,12 +5,12 @@
 -->
 <manifest>
   <remote name="verification" fetch="."/>
-  
+
   <default remote="verification" revision="master"/>
-  
+
   <project name="HOL" path="HOL4" revision="ab03cec5200c8b23f9ba60c5cea958cfcd0cd158" dest-branch="successful-decompile"/>
   <project name="graph-refine" revision="8924af0c61c3c863db7957e0ebac7ae1ceefad9d" dest-branch="master"/>
-  <project name="isabelle" revision="refs/tags/Isabelle2022" dest-branch="ts-2022"/>
+  <project name="isabelle" revision="refs/tags/Isabelle2023" dest-branch="ts-2023"/>
   <project name="l4v" revision="e7cca6ab03e4a1e4164b6bd9e3c2fc4d1574bbcd" dest-branch="master"/>
   <project name="polyml" path="HOL4/polyml" revision="bf2020d077bfbb1c5911dcef20bd275c95da7162" dest-branch="successful-decompile"/>
   <project name="seL4" revision="3534865d334979737971e22fbf1bf777c6dd4b06"/>
diff --git a/devel.xml b/devel.xml
index 7bf04258..45049e96 100644
--- a/devel.xml
+++ b/devel.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" />
   <project name="polyml" path="HOL4/polyml" revision="successful-decompile"/>
   <project name="seL4" revision="3534865d334979737971e22fbf1bf777c6dd4b06"/>