diff -r 3d33847dc911 -r 982f0bf34804 lib/Tools/scalac
--- a/lib/Tools/scalac	Mon Jan 22 22:45:45 2018 +0100
+++ b/lib/Tools/scalac	Tue Jan 23 16:37:57 2018 +0100
@@ -7,5 +7,5 @@
 isabelle_admin_build jars || exit $?
 
 isabelle_scala scalac -Dfile.encoding=UTF-8 \
+  "-Djava.ext.dirs=$(platform_path "$ISABELLE_JDK_HOME/jre/lib/ext")" \
   -classpath "$(platform_path "$ISABELLE_CLASSPATH")" "$@"
-