diff --git a/Source/MIPSAssembler.h b/Source/MIPSAssembler.h
index 070e5381b..a84ea0a13 100644
--- a/Source/MIPSAssembler.h
+++ b/Source/MIPSAssembler.h
@@ -2,6 +2,7 @@
 
 #include "Types.h"
 #include <map>
+#include <cstddef>
 
 class CMIPSAssembler
 {