diff --git a/py/mpstate.h b/py/mpstate.h
index 10a5db8..a2366df 100644
--- a/py/mpstate.h
+++ b/py/mpstate.h
@@ -32,7 +32,7 @@
 #include "py/misc.h"
 #include "py/nlr.h"
 #include "py/obj.h"
-#include "py/objlist.h" // in case port needs mp_obj_list_t in root pointers
+#include "py/objlist.h"
 #include "py/objexcept.h"
 
 // This file contains structures defining the state of the Micro Python
@@ -66,6 +66,10 @@
     uint16_t gc_auto_collect_enabled;
 
     mp_uint_t gc_last_free_atb_index;
+
+    #if MICROPY_PY_GC_COLLECT_RETVAL
+    mp_uint_t gc_collected;
+    #endif
 } mp_state_mem_t;
 
 // This structure hold runtime and VM information.  It includes a section
@@ -106,6 +110,10 @@
     // dictionary for the __main__ module
     mp_obj_dict_t dict_main;
 
+    // these two lists must be initialised per port, after the call to mp_init
+    mp_obj_list_t mp_sys_path_obj;
+    mp_obj_list_t mp_sys_argv_obj;
+
     // dictionary for overridden builtins
     #if MICROPY_CAN_OVERRIDE_BUILTINS
     mp_obj_dict_t *mp_module_builtins_override_dict;