diff --git a/Mac/Lib/argvemulator.py b/Mac/Lib/argvemulator.py
index 2df597a..89d48b8 100644
--- a/Mac/Lib/argvemulator.py
+++ b/Mac/Lib/argvemulator.py
@@ -18,8 +18,8 @@
 		self.quitting = 0
 		self.ae_handlers = {}
 		# Remove the funny -psn_xxx_xxx argument
-		if sys.argv[0][:4] == '-psn':
-			del sys.argv[0]
+		if len(sys.argv) > 1 and sys.argv[1][:4] == '-psn':
+			del sys.argv[1]
 		self.installaehandler('aevt', 'oapp', self.open_app)
 		self.installaehandler('aevt', 'odoc', self.open_file)