diff --git a/lib/bs412.c b/lib/bs412.c
index b4d8fbf..422b472 100644
--- a/lib/bs412.c
+++ b/lib/bs412.c
@@ -5,7 +5,7 @@ float dbr_to_deviation(float dbr) {
 }
 
 float deviation_to_dbr(float deviation) {
-	return 20*log10f(deviation/19000.0f);
+	return 20 * log10f((deviation + 1e-6f) / 19000.0f);
 }
 
 void init_modulation_power_measure(MPXPowerMeasurement* mpx, int sample_rate) {
@@ -14,7 +14,7 @@ void init_modulation_power_measure(MPXPowerMeasurement* mpx, int sample_rate) {
 	mpx->sample_rate = sample_rate;
 }
 
-float measure_mpx(MPXPowerMeasurement* mpx, int deviation) {
+float measure_mpx(MPXPowerMeasurement* mpx, float deviation) {
 	mpx->sample += deviation;
 
 	float avg_deviation = (float)mpx->sample / mpx->i;
diff --git a/lib/bs412.h b/lib/bs412.h
index 047b629..eab4b63 100644
--- a/lib/bs412.h
+++ b/lib/bs412.h
@@ -12,4 +12,4 @@ float dbr_to_deviation(float dbr);
 float deviation_to_dbr(float deviation);
 
 void init_modulation_power_measure(MPXPowerMeasurement *mpx, int sample_rate);
-float measure_mpx(MPXPowerMeasurement *mpx, int deviation);
\ No newline at end of file
+float measure_mpx(MPXPowerMeasurement *mpx, float deviation);
\ No newline at end of file