diff --git a/client/src/cmdmain.c b/client/src/cmdmain.c
index c55c7792e..d6ff5edea 100644
--- a/client/src/cmdmain.c
+++ b/client/src/cmdmain.c
@@ -155,7 +155,7 @@ static int CmdAuto(const char *Cmd) {
     CmdPlot("");
     lf_read(false, 40000);
     char *fname = calloc(100, sizeof(uint8_t));
-    AppendDate(fname, 100, "f lf_unknown_%Y-%m-%d_%H:%M");
+    AppendDate(fname, 100, "-f lf_unknown_%Y-%m-%d_%H:%M");
     CmdSave(fname);
     free(fname);
     return PM3_SUCCESS;