diff --git a/src/processors/other/poly_octave/PolyOctaveV2FilterBank.h b/src/processors/other/poly_octave/PolyOctaveV2FilterBank.h
index 91da8a10..c84ef212 100644
--- a/src/processors/other/poly_octave/PolyOctaveV2FilterBank.h
+++ b/src/processors/other/poly_octave/PolyOctaveV2FilterBank.h
@@ -1,6 +1,7 @@
 #pragma once
 
 #include <array>
+#include <cstddef>
 
 namespace poly_octave_v2
 {