diff --git a/lib/bs412.c b/lib/bs412.c
index f527cdc..830963e 100644
--- a/lib/bs412.c
+++ b/lib/bs412.c
@@ -7,7 +7,7 @@ void init_modulation_power_measure(MPXPowerMeasurement* mpx, int sample_rate) {
 }
 
 float measure_mpx(MPXPowerMeasurement* mpx, int deviation) {
-	mpx->sample += 20*log10f(deviation/19000.0f);
+	mpx->sample += 10*log10f(deviation/19000.0f);
 	mpx->i++;
 	float modulation_power = mpx->sample/mpx->i;
 	if (mpx->i >= mpx->sample_rate) {