diff --git a/firmware/tools/fir_lpf.py b/firmware/tools/fir_lpf.py
index c9ae395b3..bbfe91e11 100644
--- a/firmware/tools/fir_lpf.py
+++ b/firmware/tools/fir_lpf.py
@@ -1,3 +1,5 @@
+#!/usr/bin/env python3
+
 import math
 
 m = 64 - 1