{
        int nongit = 0;
        char* value;
-       setup_git_directory_gently(&nongit);
+       const char *file = setup_git_directory_gently(&nongit);
 
        while (1 < argc) {
                if (!strcmp(argv[1], "--int"))
                else if (!strcmp(argv[1], "--file") || !strcmp(argv[1], "-f")) {
                        if (argc < 3)
                                usage(git_config_set_usage);
-                       setenv(CONFIG_ENVIRONMENT, argv[2], 1);
+                       if (!is_absolute_path(argv[2]) && file)
+                               file = prefix_filename(file, strlen(file),
+                                                      argv[2]);
+                       else
+                               file = argv[2];
+                       setenv(CONFIG_ENVIRONMENT, file, 1);
                        argc--;
                        argv++;
                }