diff --git a/qemu/scripts/qapi.py b/qemu/scripts/qapi.py
index e215092e..7f59f9f6 100644
--- a/qemu/scripts/qapi.py
+++ b/qemu/scripts/qapi.py
@@ -988,7 +988,7 @@ def parse_command_line(extra_options = "", extra_long_options = []):
                                         "input-file=", "output-dir="]
                                        + extra_long_options)
     except getopt.GetoptError, err:
-        print str(err)
+        print >>sys.stderr, "%s: %s" % (sys.argv[0], str(err))
         sys.exit(1)
 
     output_dir = ""
@@ -1016,4 +1016,8 @@ def parse_command_line(extra_options = "", extra_long_options = []):
         do_c = True
         do_h = True
 
+    if len(args) != 0:
+        print >>sys.stderr, "%s: too many arguments" % sys.argv[0]
+        sys.exit(1)
+
     return (input_file, output_dir, do_c, do_h, prefix, extra_opts)