diff --git a/tools/perf/builtin-report.c b/tools/perf/builtin-report.c
index 91a3762b4211..aef59f318a67 100644
--- a/tools/perf/builtin-report.c
+++ b/tools/perf/builtin-report.c
@@ -941,8 +941,7 @@ parse_time_quantum(const struct option *opt, const char *arg,
 		pr_err("time quantum cannot be 0");
 		return -1;
 	}
-	while (isspace(*end))
-		end++;
+	end = skip_spaces(end);
 	if (*end == 0)
 		return 0;
 	if (!strcmp(end, "s")) {