diff --git a/bootstraptest/test_ractor.rb b/bootstraptest/test_ractor.rb
index ed80dd0862..6c3a45148c 100644
--- a/bootstraptest/test_ractor.rb
+++ b/bootstraptest/test_ractor.rb
@@ -2370,3 +2370,24 @@ assert_equal 'ok', <<~'RUBY'
     :ok
   end
 RUBY
+
+assert_equal 'ok', <<~'RUBY'
+  begin
+    100.times do |i|
+      Ractor.new(i) do |j|
+        1000.times do |i|
+          "#{j}-#{i}"
+        end
+      end
+      pid = fork do
+        GC.verify_internal_consistency
+      end
+      _, status = Process.waitpid2 pid
+      raise unless status.success?
+    end
+
+    :ok
+  rescue NotImplementedError
+    :ok
+  end
+RUBY
diff --git a/gc/default/default.c b/gc/default/default.c
index b6a9dfa1f5..9a2efab562 100644
--- a/gc/default/default.c
+++ b/gc/default/default.c
@@ -622,6 +622,8 @@ typedef struct rb_objspace {
     rb_postponed_job_handle_t finalize_deferred_pjob;
 
     unsigned long live_ractor_cache_count;
+
+    int fork_vm_lock_lev;
 } rb_objspace_t;
 
 #ifndef HEAP_PAGE_ALIGN_LOG
@@ -9324,12 +9326,20 @@ gc_malloc_allocations(VALUE self)
 void
 rb_gc_impl_before_fork(void *objspace_ptr)
 {
-    /* no-op */
+    rb_objspace_t *objspace = objspace_ptr;
+
+    objspace->fork_vm_lock_lev = RB_GC_VM_LOCK();
+    rb_gc_vm_barrier();
 }
 
 void
 rb_gc_impl_after_fork(void *objspace_ptr, rb_pid_t pid)
 {
+    rb_objspace_t *objspace = objspace_ptr;
+
+    RB_GC_VM_UNLOCK(objspace->fork_vm_lock_lev);
+    objspace->fork_vm_lock_lev = 0;
+
     if (pid == 0) { /* child process */
         rb_gc_ractor_newobj_cache_foreach(gc_ractor_newobj_cache_clear, NULL);
     }