diff --git a/radio/interpolation/PolyPhase.hpp b/radio/interpolation/PolyPhase.hpp
index 4bdc672..685db91 100644
--- a/radio/interpolation/PolyPhase.hpp
+++ b/radio/interpolation/PolyPhase.hpp
@@ -7,6 +7,7 @@
 #include <cpp/radio/FirComplex.hpp>
 #include <fir/fir2.h>
 #include <memory.h>
+#include <string.h>
 
 namespace Radio
 {