diff --git a/debug.c b/debug.c
index 546ffc440f..4717a0bc9c 100644
--- a/debug.c
+++ b/debug.c
@@ -226,7 +226,7 @@ ruby_env_debug_option(const char *str, int len, void *arg)
     }
 
     if (NAME_MATCH("gc_stress")) {
-        rb_gc_stress_set(Qtrue);
+        rb_gc_initial_stress_set(Qtrue);
         return 1;
     }
     SET_WHEN("core", ruby_enable_coredump, 1);
diff --git a/gc.c b/gc.c
index 8812c0fea5..04df9dc71b 100644
--- a/gc.c
+++ b/gc.c
@@ -1876,10 +1876,22 @@ calloc1(size_t n)
     return calloc(1, n);
 }
 
+static VALUE initial_stress = Qfalse;
+
+void
+rb_gc_initial_stress_set(VALUE flag)
+{
+    initial_stress = flag;
+}
+
 rb_objspace_t *
 rb_objspace_alloc(void)
 {
     rb_objspace_t *objspace = calloc1(sizeof(rb_objspace_t));
+
+    objspace->flags.gc_stressful = RTEST(initial_stress);
+    objspace->gc_stress_mode = initial_stress;
+
     objspace->flags.measure_gc = 1;
     malloc_limit = gc_params.malloc_limit_min;
     objspace->finalize_deferred_pjob = rb_postponed_job_preregister(0, gc_finalize_deferred, objspace);
@@ -1898,8 +1910,6 @@ rb_objspace_alloc(void)
 
     rb_darray_make_without_gc(&objspace->weak_references, 0);
 
-    dont_gc_on();
-
     return objspace;
 }
 
@@ -8951,7 +8961,7 @@ gc_start(rb_objspace_t *objspace, unsigned int reason)
     /* reason may be clobbered, later, so keep set immediate_sweep here */
     objspace->flags.immediate_sweep = !!(reason & GPR_FLAG_IMMEDIATE_SWEEP);
 
-    if (!heap_allocated_pages) return FALSE; /* heap is not ready */
+    if (!heap_allocated_pages) return TRUE; /* heap is not ready */
     if (!(reason & GPR_FLAG_METHOD) && !ready_to_gc(objspace)) return TRUE; /* GC is not allowed */
 
     GC_ASSERT(gc_mode(objspace) == gc_mode_none);
@@ -11147,20 +11157,14 @@ gc_stress_get(rb_execution_context_t *ec, VALUE self)
     return ruby_gc_stress_mode;
 }
 
-void
-rb_gc_stress_set(VALUE flag)
+static VALUE
+gc_stress_set_m(rb_execution_context_t *ec, VALUE self, VALUE flag)
 {
     rb_objspace_t *objspace = &rb_objspace;
 
     objspace->flags.gc_stressful = RTEST(flag);
     objspace->gc_stress_mode = flag;
-}
 
-static VALUE
-gc_stress_set_m(rb_execution_context_t *ec, VALUE self, VALUE flag)
-{
-
-    rb_gc_stress_set(flag);
     return flag;
 }
 
diff --git a/internal/gc.h b/internal/gc.h
index 82a1b901f8..5b1180fd91 100644
--- a/internal/gc.h
+++ b/internal/gc.h
@@ -223,7 +223,7 @@ void rb_gc_remove_weak(VALUE parent_obj, VALUE *ptr);
 
 void rb_gc_ref_update_table_values_only(st_table *tbl);
 
-void rb_gc_stress_set(VALUE flag);
+void rb_gc_initial_stress_set(VALUE flag);
 
 #define rb_gc_mark_and_move_ptr(ptr) do { \
     VALUE _obj = (VALUE)*(ptr); \