diff --git a/Python/getopt.c b/Python/getopt.c
index 7c1d605..1baf872 100644
--- a/Python/getopt.c
+++ b/Python/getopt.c
@@ -83,7 +83,18 @@
 
 	if ( (option = *opt_ptr++) == L'\0')
 		return -1;
-	
+
+	if (option == 'J') {
+		fprintf(stderr, "-J is reserved for Jython\n");
+		return '_';
+	}
+
+	if (option == 'X') {
+		fprintf(stderr,
+			"-X is reserved for non-standard arguments\n");
+		return '_';
+	}
+
 	if ((ptr = wcschr(optstring, option)) == NULL) {
 		if (_PyOS_opterr)
 		  fprintf(stderr, "Unknown option: -%c\n", (char)option);