diff --git a/Mac/Python/macmain.c b/Mac/Python/macmain.c
index b86b528..71b42e9 100644
--- a/Mac/Python/macmain.c
+++ b/Mac/Python/macmain.c
@@ -316,8 +316,14 @@
 		*argcp = 1;
 		*argvp = emb_argv;
 	} else {
-		/* Create argc/argv. Do it before we go into the options event loop. */
-		*argcp = PyMac_GetArgv(argvp, PyMac_options.noargs);
+		/* Create argc/argv. Do it before we go into the options event loop.
+		** In MachoPython we skip this step if we already have plausible
+		** command line arguments.
+		*/
+#if TARGET_API_MAC_OSX
+		if (*argcp == 2 && strncmp((*argvp)[1], "-psn_", 5) == 0)
+#endif
+			*argcp = PyMac_GetArgv(argvp, PyMac_options.noargs);
 #if !TARGET_API_MAC_OSX
 #ifndef NO_ARGV0_CHDIR
 		if (*argcp >= 1 && (*argvp)[0] && (*argvp)[0][0]) {