diff --git a/Modules/main.c b/Modules/main.c
index 4af2e77..46eb4bb 100644
--- a/Modules/main.c
+++ b/Modules/main.c
@@ -45,7 +45,7 @@
 static int  orig_argc;
 
 /* command line options */
-#define BASE_OPTS L"bBc:dEhim:OStuvVW:xX?"
+#define BASE_OPTS L"bBc:dEhiJm:OStuvVW:xX?"
 
 #define PROGRAM_OPTS BASE_OPTS
 
@@ -345,6 +345,8 @@
 			Py_InteractiveFlag++;
 			break;
 
+		/* case 'J': reserved for Jython */
+
 		case 'O':
 			Py_OptimizeFlag++;
 			break;
@@ -378,6 +380,8 @@
 			skipfirstline = 1;
 			break;
 
+		/* case 'X': reserved for non-standard arguments */
+
 		case 'h':
 		case '?':
 			help++;