diff --git a/include/pocketpy/pocketpy.h b/include/pocketpy/pocketpy.h
index 3c05a016..a90ad65e 100644
--- a/include/pocketpy/pocketpy.h
+++ b/include/pocketpy/pocketpy.h
@@ -30,7 +30,7 @@ typedef void (*py_Dtor)(void*);
 
 #ifdef PK_IS_PUBLIC_INCLUDE
 typedef struct py_TValue {
-    char _[16];
+    int64_t _[2];
 } py_TValue;
 #endif