2 files changed, 2 insertions, 2 deletions

diff --git a/tools/perf/builtin-diff.c b/tools/perf/builtin-diff.c
index f800fc95f5d7..473887d1d61a 100644
--- a/tools/perf/builtin-diff.c
+++ b/tools/perf/builtin-diff.c
@@ -802,7 +802,7 @@ static const struct option options[] = {
         OPT_STRING('s', "sort", &sort_order, "key[,key2...]",
                    "sort by key(s): pid, comm, dso, symbol, parent, cpu, srcline, ..."
                    " Please refer the man page for the complete list."),
-        OPT_STRING('t', "field-separator", &symbol_conf.field_sep, "separator",
+        OPT_STRING_NOEMPTY('t', "field-separator", &symbol_conf.field_sep, "separator",
                    "separator for columns, no spaces will be added between "
                    "columns '.' is reserved."),
         OPT_STRING(0, "symfs", &symbol_conf.symfs, "directory",
diff --git a/tools/perf/builtin-mem.c b/tools/perf/builtin-mem.c
index 46c69318de84..b4dcf0bfc029 100644
--- a/tools/perf/builtin-mem.c
+++ b/tools/perf/builtin-mem.c
@@ -286,7 +286,7 @@ int cmd_mem(int argc, const char **argv, const char *prefix __maybe_unused)
                    "input file name"),
         OPT_STRING('C', "cpu", &mem.cpu_list, "cpu",
                    "list of cpus to profile"),
-        OPT_STRING('x', "field-separator", &symbol_conf.field_sep,
+        OPT_STRING_NOEMPTY('x', "field-separator", &symbol_conf.field_sep,
                    "separator",
                    "separator for columns, no spaces will be added"
                    " between columns '.' is reserved."),