diff --git a/openbis/dist/server/register-master-data.sh b/openbis/dist/server/register-master-data.sh
index 0ed3ec8c9ba872bf074863a0a4c8a60db6f9534b..ab4b3f61541b01695e80ac2d2a44d534d4849706 100755
--- a/openbis/dist/server/register-master-data.sh
+++ b/openbis/dist/server/register-master-data.sh
@@ -18,11 +18,10 @@ if [ ! -x "$JVM" ]; then
   exit 1
 fi
 
-disableJythonByProperty
-
 LIB=$BASE/../webapps/$APPLICATION_NAME/WEB-INF/lib
 
+# always Jython 2.5 is used independent which one is enabled. Fixing bug SSDM-4473
 $JVM \
  -Dorg.eclipse.jetty.util.log.class=org.eclipse.jetty.util.log.StrErrLog \
- -cp $LIB/\* \
+ -cp $LIB/jython-2.5.2.jar_disabled:$LIB/\* \
  ch.systemsx.cisd.openbis.generic.server.jython.api.v1.impl.MasterDataRegistrationScriptRunnerStandalone "$@"