diff --git a/src/ipa/raspberrypi/controller/pwl.h b/src/ipa/raspberrypi/controller/pwl.h
index 546482cd..aacf6039 100644
--- a/src/ipa/raspberrypi/controller/pwl.h
+++ b/src/ipa/raspberrypi/controller/pwl.h
@@ -6,6 +6,7 @@
  */
 #pragma once
 
+#include <functional>
 #include <math.h>
 #include <vector>