diff --git a/gc.c b/gc.c
index 9d59163ee0..10ab04fb81 100644
--- a/gc.c
+++ b/gc.c
@@ -581,7 +581,6 @@ typedef struct gc_function_map {
     void (*ractor_cache_free)(void *objspace_ptr, void *cache);
     void (*set_params)(void *objspace_ptr);
     void (*init)(void);
-    void (*initial_stress_set)(VALUE flag);
     size_t *(*size_pool_sizes)(void *objspace_ptr);
     // Shutdown
     void (*shutdown_free_objects)(void *objspace_ptr);
@@ -711,7 +710,6 @@ ruby_external_gc_init(void)
     load_external_gc_func(ractor_cache_free);
     load_external_gc_func(set_params);
     load_external_gc_func(init);
-    load_external_gc_func(initial_stress_set);
     load_external_gc_func(size_pool_sizes);
     // Shutdown
     load_external_gc_func(shutdown_free_objects);
@@ -789,7 +787,6 @@ ruby_external_gc_init(void)
 # define rb_gc_impl_ractor_cache_free rb_gc_functions.ractor_cache_free
 # define rb_gc_impl_set_params rb_gc_functions.set_params
 # define rb_gc_impl_init rb_gc_functions.init
-# define rb_gc_impl_initial_stress_set rb_gc_functions.initial_stress_set
 # define rb_gc_impl_size_pool_sizes rb_gc_functions.size_pool_sizes
 // Shutdown
 # define rb_gc_impl_shutdown_free_objects rb_gc_functions.shutdown_free_objects
@@ -857,6 +854,8 @@ ruby_external_gc_init(void)
 # define rb_gc_impl_copy_attributes rb_gc_functions.copy_attributes
 #endif
 
+static VALUE initial_stress = Qfalse;
+
 void *
 rb_objspace_alloc(void)
 {
@@ -868,6 +867,7 @@ rb_objspace_alloc(void)
     ruby_current_vm_ptr->gc.objspace = objspace;
 
     rb_gc_impl_objspace_init(objspace);
+    rb_gc_impl_stress_set(objspace, initial_stress);
 
     return objspace;
 }
@@ -3450,7 +3450,7 @@ gc_stress_set_m(rb_execution_context_t *ec, VALUE self, VALUE flag)
 void
 rb_gc_initial_stress_set(VALUE flag)
 {
-    rb_gc_impl_initial_stress_set(flag);
+    initial_stress = flag;
 }
 
 size_t *
diff --git a/gc/default.c b/gc/default.c
index f5893a8119..4ea56c4120 100644
--- a/gc/default.c
+++ b/gc/default.c
@@ -1556,14 +1556,6 @@ minimum_slots_for_size_pool(rb_objspace_t *objspace, rb_size_pool_t *size_pool)
     return gc_params.size_pool_init_slots[size_pool_idx];
 }
 
-static VALUE initial_stress = Qfalse;
-
-void
-rb_gc_impl_initial_stress_set(VALUE flag)
-{
-    initial_stress = flag;
-}
-
 static int
 object_id_cmp(st_data_t x, st_data_t y)
 {
@@ -9360,9 +9352,6 @@ rb_gc_impl_objspace_init(void *objspace_ptr)
 
     gc_config_full_mark_set(TRUE);
 
-    objspace->flags.gc_stressful = RTEST(initial_stress);
-    objspace->gc_stress_mode = initial_stress;
-
     objspace->flags.measure_gc = true;
     malloc_limit = gc_params.malloc_limit_min;
     objspace->finalize_deferred_pjob = rb_postponed_job_preregister(0, gc_finalize_deferred, objspace);
diff --git a/gc/gc_impl.h b/gc/gc_impl.h
index c83e8ce28d..925c336f95 100644
--- a/gc/gc_impl.h
+++ b/gc/gc_impl.h
@@ -32,7 +32,6 @@ GC_IMPL_FN void *rb_gc_impl_ractor_cache_alloc(void *objspace_ptr);
 GC_IMPL_FN void rb_gc_impl_ractor_cache_free(void *objspace_ptr, void *cache);
 GC_IMPL_FN void rb_gc_impl_set_params(void *objspace_ptr);
 GC_IMPL_FN void rb_gc_impl_init(void);
-GC_IMPL_FN void rb_gc_impl_initial_stress_set(VALUE flag);
 GC_IMPL_FN size_t *rb_gc_impl_size_pool_sizes(void *objspace_ptr);
 // Shutdown
 GC_IMPL_FN void rb_gc_impl_shutdown_free_objects(void *objspace_ptr);