Index: Python/getopt.c
===================================================================
--- Python/getopt.c	(revision 62290)
+++ Python/getopt.c	(working copy)
@@ -80,7 +80,12 @@
 
 	if ( (option = *opt_ptr++) == '\0')
 		return -1;
-	
+
+	if (option == 'J') {
+		fprintf(stderr, "-J is reserved for Jython\n");
+		return '_';
+	}
+
 	if ((ptr = strchr(optstring, option)) == NULL) {
 		if (_PyOS_opterr)
 			fprintf(stderr, "Unknown option: -%c\n", option);
Index: Modules/main.c
===================================================================
--- Modules/main.c	(revision 62290)
+++ Modules/main.c	(working copy)
@@ -83,6 +83,7 @@
 -V     : print the Python version number and exit (also --version)\n\
 -W arg : warning control; arg is action:message:category:module:lineno\n\
 -x     : skip first line of source, allowing use of non-Unix forms of #!cmd\n\
+-J     : reserved for Jython\n\
 ";
 static char *usage_4 = "\
 -3     : warn about Python 3.x incompatibilities\n\