diff --git a/libraries/Filter/Butter.h b/libraries/Filter/Butter.h
index 02eb2e064d..36ac1f420e 100644
--- a/libraries/Filter/Butter.h
+++ b/libraries/Filter/Butter.h
@@ -1,7 +1,5 @@
 #pragma once
 
-#include <AP_HAL/AP_HAL.h>
-
 template <typename Coefficients>
 class Butter2
 {