Index: C:/workspace/jython/jython/src/shell/jython.bat
===================================================================
--- C:/workspace/jython/jython/src/shell/jython.bat	(revision 6085)
+++ C:/workspace/jython/jython/src/shell/jython.bat	(working copy)
@@ -160,7 +160,13 @@
 goto scanArgs
 
 :argsDone
-if not defined _BOOT_CP set CLASSPATH=%_CP:"=%;%CLASSPATH:"=%
+if not defined _BOOT_CP (
+  if defined CLASSPATH (
+    set CLASSPATH=%_CP:"=%;%CLASSPATH:"=%
+  ) else (
+    set CLASSPATH=%_CP:"=%
+  )
+)
 %_JAVA_CMD% %_JAVA_OPTS% %_JAVA_STACK% %_BOOT_CP% -Dpython.home=%_JYTHON_HOME% -Dpython.executable="%~f0" -classpath "%CLASSPATH%" org.python.util.jython %_JYTHON_OPTS% %_JYTHON_ARGS% %_ARGS%
 set E=%ERRORLEVEL%