diff --git a/gc/default/default.c b/gc/default/default.c
index be5385f166..132dbcb5fa 100644
--- a/gc/default/default.c
+++ b/gc/default/default.c
@@ -505,7 +505,6 @@ typedef struct rb_objspace {
         unsigned int during_compacting : 1;
         unsigned int during_reference_updating : 1;
         unsigned int gc_stressful: 1;
-        unsigned int has_newobj_hook: 1;
         unsigned int during_minor_gc : 1;
         unsigned int during_incremental_marking : 1;
         unsigned int measure_gc : 1;
@@ -1520,7 +1519,6 @@ rb_gc_impl_set_event_hook(void *objspace_ptr, const rb_event_flag_t event)
 {
     rb_objspace_t *objspace = objspace_ptr;
     objspace->hook_events = event & RUBY_INTERNAL_EVENT_OBJSPACE_MASK;
-    objspace->flags.has_newobj_hook = !!(objspace->hook_events & RUBY_INTERNAL_EVENT_NEWOBJ);
 }
 
 unsigned long long