diff --git a/iterhash.cpp b/iterhash.cpp
index ce2e5cc3..f8be97d9 100644
--- a/iterhash.cpp
+++ b/iterhash.cpp
@@ -6,6 +6,7 @@
 
 #include "iterhash.h"
 #include "misc.h"
+#include "cpu.h"
 
 NAMESPACE_BEGIN(CryptoPP)