diff --git a/src/vty/command.c b/src/vty/command.c
index 3112fee..bb6a665 100644
--- a/src/vty/command.c
+++ b/src/vty/command.c
@@ -3067,13 +3067,15 @@
       show_uptime_cmd, "show uptime", SHOW_STR "Displays how long the program has been running\n")
 {
 	struct timespec now;
-	osmo_clock_gettime(CLOCK_MONOTONIC, &now);
+	struct timespec uptime;
 
-	time_t uptime = now.tv_sec - starttime.tv_sec;
-	int d = uptime / (3600 * 24);
-	int h = uptime / 3600 % 24;
-	int m = uptime / 60 % 60;
-	int s = uptime % 60;
+	osmo_clock_gettime(CLOCK_MONOTONIC, &now);
+	timespecsub(&now, &starttime, &uptime);
+
+	int d = uptime.tv_sec / (3600 * 24);
+	int h = uptime.tv_sec / 3600 % 24;
+	int m = uptime.tv_sec / 60 % 60;
+	int s = uptime.tv_sec % 60;
 
 	vty_out(vty, "%s has been running for %dd %dh %dm %ds%s", host.app_info->name, d, h, m, s, VTY_NEWLINE);