diff --git a/tools/perf/util/time-utils.c b/tools/perf/util/time-utils.c
index 302443921681..1b91ccd4d523 100644
--- a/tools/perf/util/time-utils.c
+++ b/tools/perf/util/time-utils.c
@@ -20,7 +20,7 @@ int parse_nsec_time(const char *str, u64 *ptime)
 	u64 time_sec, time_nsec;
 	char *end;
 
-	time_sec = strtoul(str, &end, 10);
+	time_sec = strtoull(str, &end, 10);
 	if (*end != '.' && *end != '\0')
 		return -1;
 
@@ -38,7 +38,7 @@ int parse_nsec_time(const char *str, u64 *ptime)
 		for (i = strlen(nsec_buf); i < 9; i++)
 			nsec_buf[i] = '0';
 
-		time_nsec = strtoul(nsec_buf, &end, 10);
+		time_nsec = strtoull(nsec_buf, &end, 10);
 		if (*end != '\0')
 			return -1;
 	} else