1 files changed, 5 insertions, 0 deletions
diff --git a/vm_core.h b/vm_core.h
index dfce1785ac..bc221a74cb 100644
--- a/vm_core.h
+++ b/vm_core.h
@@ -507,6 +507,8 @@ typedef struct rb_ensure_list {
     struct rb_ensure_entry entry;
 } rb_ensure_list_t;
 
+typedef char rb_thread_id_string_t[sizeof(rb_nativethread_id_t) * 2 + 3];
+
 typedef struct rb_thread_struct {
     struct list_node vmlt_node;
     VALUE self;
@@ -546,6 +548,9 @@ typedef struct rb_thread_struct {
 
     /* thread control */
     rb_nativethread_id_t thread_id;
+#ifdef NON_SCALAR_THREAD_ID
+    rb_thread_id_string_t thread_id_string;
+#endif
     enum rb_thread_status status;
     int to_kill;
     int priority;