"regex filter to identify parent, see: '--sort parent'"),
        OPT_BOOLEAN('x', "exclude-other", &exclude_other,
                    "Only display entries with parent-match"),
-       OPT_CALLBACK_DEFAULT('c', "callchain", NULL, "output_type,min_percent",
+       OPT_CALLBACK_DEFAULT('g', "call-graph", NULL, "output_type,min_percent",
                     "Display callchains using output_type and min percent threshold. "
-                    "Default: flat,0", &parse_callchain_opt, callchain_default_opt),
+                    "Default: fractal,0.5", &parse_callchain_opt, callchain_default_opt),
        OPT_STRING('d', "dsos", &dso_list_str, "dso[,dso...]",
                   "only consider symbols in these dsos"),
        OPT_STRING('C', "comms", &comm_list_str, "comm[,comm...]",