const char *prefix = NULL;
        int prefix_length = -1;
        int no_more_flags = 0;
+       int hashstdin = 0;
 
        git_config(git_default_config);
 
                        else if (!strcmp(argv[i], "--help"))
                                usage(hash_object_usage);
                        else if (!strcmp(argv[i], "--stdin")) {
-                               hash_stdin(type, write_object);
+                               if (hashstdin)
+                                       die("Multiple --stdin arguments are not supported");
+                               hashstdin = 1;
                        }
                        else
                                usage(hash_object_usage);
                }
                else {
                        const char *arg = argv[i];
+
+                       if (hashstdin) {
+                               hash_stdin(type, write_object);
+                               hashstdin = 0;
+                       }
                        if (0 <= prefix_length)
                                arg = prefix_filename(prefix, prefix_length,
                                                      arg);
                        no_more_flags = 1;
                }
        }
+       if (hashstdin)
+               hash_stdin(type, write_object);
        return 0;
 }