diff --git a/libraries/Filter/LowPassFilter.h b/libraries/Filter/LowPassFilter.h
index 32278e8d8a..09fb1601a1 100644
--- a/libraries/Filter/LowPassFilter.h
+++ b/libraries/Filter/LowPassFilter.h
@@ -78,7 +78,7 @@ template <class T>
 void LowPassFilter<T>::set_cutoff_frequency(float time_step, float cutoff_freq)
 {
     // calculate alpha
-    float rc = 1/(2*M_PI*cutoff_freq);
+    float rc = 1/(2*(float)M_PI*cutoff_freq);
     _alpha = time_step / (time_step + rc);
 }