diff --git a/LEGO1/mxstring.cpp b/LEGO1/mxstring.cpp
index e2f24cab..e82d431a 100644
--- a/LEGO1/mxstring.cpp
+++ b/LEGO1/mxstring.cpp
@@ -1,7 +1,11 @@
 #include "mxstring.h"
+#include "decomp.h"
+
 #include <stdlib.h>
 #include <string.h>
 
+DECOMP_SIZE_ASSERT(MxString, 0x10)
+
 // OFFSET: LEGO1 0x100ae200
 MxString::MxString()
 {