diff -r e5fe4d40326d -r 2d658beb815b src/Pure/Admin/isabelle_cronjob.scala
--- a/src/Pure/Admin/isabelle_cronjob.scala	Sat Jun 20 21:44:43 2020 +0200
+++ b/src/Pure/Admin/isabelle_cronjob.scala	Sat Jun 20 22:35:24 2020 +0200
@@ -340,6 +340,7 @@
         Remote_Build("AFP2", "lrzcloud2", actual_host = "10.195.4.41", self_update = true,
           proxy_host = "lxbroy10", proxy_user = "i21isatest",
           options = "-m32 -M1x8 -t AFP" +
+            """ -e 'ISABELLE_TOOL_JAVA_OPTIONS="$ISABELLE_TOOL_JAVA_OPTIONS -Xmx8g"'""" +
             " -e ISABELLE_GHC=ghc" +
             " -e ISABELLE_MLTON=mlton" +
             " -e ISABELLE_OCAML=ocaml -e ISABELLE_OCAMLC=ocamlc -e ISABELLE_OCAMLFIND=ocamlfind" +