diff --git a/src/main/common/filter.c b/src/main/common/filter.c
index 8258103f4..3e0de982b 100644
--- a/src/main/common/filter.c
+++ b/src/main/common/filter.c
@@ -42,7 +42,7 @@ FAST_CODE float nullFilterApply(filter_t *filter, float input)
 
 // PT1 Low Pass filter
 
-float pt1FilterGain(uint8_t f_cut, float dT)
+float pt1FilterGain(uint16_t f_cut, float dT)
 {
     float RC = 1 / ( 2 * M_PI_FLOAT * f_cut);
     return dT / (RC + dT);
diff --git a/src/main/common/filter.h b/src/main/common/filter.h
index 08257cb59..61ae82ad5 100644
--- a/src/main/common/filter.h
+++ b/src/main/common/filter.h
@@ -129,7 +129,7 @@ float lmaSmoothingUpdate(laggedMovingAverage_t *filter, float input);
 // not exactly correct, but very very close and much much faster
 #define filterGetNotchQApprox(centerFreq, cutoff)   ((float)(cutoff * centerFreq) / ((float)(centerFreq - cutoff) * (float)(centerFreq + cutoff)))
 
-float pt1FilterGain(uint8_t f_cut, float dT);
+float pt1FilterGain(uint16_t f_cut, float dT);
 void pt1FilterInit(pt1Filter_t *filter, float k);
 float pt1FilterApply(pt1Filter_t *filter, float input);