diff --git a/src/cpu/cpu.cpp b/src/cpu/cpu.cpp
index da74e8ec..9c9d5668 100644
--- a/src/cpu/cpu.cpp
+++ b/src/cpu/cpu.cpp
@@ -19,6 +19,7 @@
 
 #include <assert.h>
 #include <sstream>
+#include <stddef.h>
 #include "dosbox.h"
 #include "cpu.h"
 #include "memory.h"