diff --git a/src/cpu.c b/src/cpu.c
index 92e448e..9bfe7cd 100644
--- a/src/cpu.c
+++ b/src/cpu.c
@@ -40,6 +40,8 @@ void cpu_update(struct cpu_sensors_t *c) {
 
 	c->ptotal = (float)(curr.energy - prev.energy) / (float)timespec_diff_us(&curr.ts, &prev.ts);
 	prev = curr;
+	if (c->ptotal > 500.0f || c->ptotal < 0.0f)
+		c->ptotal = 0.0f;
 
 	// lots of reads but still faster than reading /proc/cpuinfo
 	c->avg_freq = 0;