diff --git a/ext/fiddle/closure.c b/ext/fiddle/closure.c
index 2b4cdb66..35930815 100644
--- a/ext/fiddle/closure.c
+++ b/ext/fiddle/closure.c
@@ -61,7 +61,7 @@ const rb_data_type_t closure_data_type = {
         .dfree = dealloc,
         .dsize = closure_memsize
     },
-    .flags = RUBY_TYPED_FREE_IMMEDIATELY | RUBY_TYPED_WB_PROTECTED,
+    .flags = FIDDLE_DEFAULT_TYPED_DATA_FALGS,
 };
 
 struct callback_args {
@@ -300,6 +300,7 @@ initialize_body(VALUE user_data)
         cl->argv[i] = rb_fiddle_int_to_ffi_type(NUM2INT(arg));
     }
     cl->argv[argc] = NULL;
+    OBJ_FREEZE_RAW(normalized_args);
 
     ret = rb_fiddle_type_ensure(ret);
     rb_iv_set(data->self, "@ctype", ret);
diff --git a/ext/fiddle/extconf.rb b/ext/fiddle/extconf.rb
index 2d85b3ee..14758237 100644
--- a/ext/fiddle/extconf.rb
+++ b/ext/fiddle/extconf.rb
@@ -218,6 +218,8 @@ def enable_debug_build_flag(flags)
   $LOCAL_LIBS.prepend("#{libffi.a} ").strip! # to exts.mk
   $INCFLAGS.gsub!(/-I#{libffi.dir}/, '-I$(LIBFFI_DIR)')
 end
+
+have_func("rb_str_to_interned_str")
 create_makefile 'fiddle' do |conf|
   if !libffi
     next conf << "LIBFFI_CLEAN = none\n"
diff --git a/ext/fiddle/fiddle.h b/ext/fiddle/fiddle.h
index 348baa9a..83ddc7b1 100644
--- a/ext/fiddle/fiddle.h
+++ b/ext/fiddle/fiddle.h
@@ -236,5 +236,15 @@ VALUE rb_fiddle_new_function(VALUE address, VALUE arg_types, VALUE ret_type);
 typedef void (*rb_fiddle_freefunc_t)(void*);
 VALUE rb_fiddle_ptr_new_wrap(void *ptr, long size, rb_fiddle_freefunc_t func, VALUE wrap0, VALUE wrap1);
 
+enum {
+    FIDDLE_DEFAULT_TYPED_DATA_FALGS = (
+        RUBY_TYPED_FREE_IMMEDIATELY |
+        RUBY_TYPED_WB_PROTECTED |
+#ifdef RUBY_TYPED_FROZEN_SHAREABLE
+        RUBY_TYPED_FROZEN_SHAREABLE |
+#endif
+        0)
+};
+
 #endif
 /* vim: set noet sws=4 sw=4: */
diff --git a/ext/fiddle/function.c b/ext/fiddle/function.c
index 5469e09e..a8acddbe 100644
--- a/ext/fiddle/function.c
+++ b/ext/fiddle/function.c
@@ -59,7 +59,7 @@ const rb_data_type_t function_data_type = {
         .dfree = deallocate,
         .dsize = function_memsize
     },
-    .flags = RUBY_TYPED_FREE_IMMEDIATELY | RUBY_TYPED_WB_PROTECTED,
+    .flags = FIDDLE_DEFAULT_TYPED_DATA_FALGS,
 };
 
 static VALUE
@@ -153,6 +153,9 @@ initialize(int argc, VALUE argv[], VALUE self)
         rb_get_kwargs(kwargs, kw, 0, kw_max_, args);
         if (args[kw_name] != Qundef) {
             name = args[kw_name];
+#ifdef HAVE_RB_STR_TO_INTERNED_STR
+            name = rb_str_to_interned_str(name);
+#endif
         }
         if (args[kw_need_gvl] != Qundef) {
             need_gvl = args[kw_need_gvl];
diff --git a/ext/fiddle/handle.c b/ext/fiddle/handle.c
index 8ba41695..808e44e2 100644
--- a/ext/fiddle/handle.c
+++ b/ext/fiddle/handle.c
@@ -56,7 +56,8 @@ static const rb_data_type_t fiddle_handle_data_type = {
         .dfree = fiddle_handle_free,
         .dsize = fiddle_handle_memsize
     },
-    .flags = RUBY_TYPED_WB_PROTECTED,
+    .flags = FIDDLE_DEFAULT_TYPED_DATA_FALGS & ~RUBY_TYPED_FREE_IMMEDIATELY,
+    /* keeping while its symbols are referred. */
 };
 
 /*
diff --git a/ext/fiddle/memory_view.c b/ext/fiddle/memory_view.c
index fa66fc2c..140c8efe 100644
--- a/ext/fiddle/memory_view.c
+++ b/ext/fiddle/memory_view.c
@@ -64,8 +64,13 @@ fiddle_memview_memsize(const void *ptr)
 }
 
 static const rb_data_type_t fiddle_memview_data_type = {
-    "fiddle/memory_view",
-    {fiddle_memview_mark, fiddle_memview_free, fiddle_memview_memsize,},
+    .wrap_struct_name = "fiddle/memory_view",
+    .function = {
+        .dmark = fiddle_memview_mark,
+        .dfree = fiddle_memview_free,
+        .dsize = fiddle_memview_memsize,
+    },
+    .flags = FIDDLE_DEFAULT_TYPED_DATA_FALGS,
 };
 
 static VALUE
diff --git a/ext/fiddle/pinned.c b/ext/fiddle/pinned.c
index 019a3020..fb03405a 100644
--- a/ext/fiddle/pinned.c
+++ b/ext/fiddle/pinned.c
@@ -24,9 +24,13 @@ pinned_memsize(const void *ptr)
 }
 
 static const rb_data_type_t pinned_data_type = {
-    "fiddle/pinned",
-    {pinned_mark, xfree, pinned_memsize, },
-    0, 0, RUBY_TYPED_FREE_IMMEDIATELY | RUBY_TYPED_WB_PROTECTED
+    .wrap_struct_name = "fiddle/pinned",
+    .function = {
+        .dmark = pinned_mark,
+        .dfree = RUBY_TYPED_DEFAULT_FREE,
+        .dsize = pinned_memsize,
+    },
+    .flags = FIDDLE_DEFAULT_TYPED_DATA_FALGS,
 };
 
 static VALUE
diff --git a/ext/fiddle/pointer.c b/ext/fiddle/pointer.c
index 1b7d7a69..cc780be6 100644
--- a/ext/fiddle/pointer.c
+++ b/ext/fiddle/pointer.c
@@ -94,7 +94,7 @@ static const rb_data_type_t fiddle_ptr_data_type = {
         .dfree = fiddle_ptr_free,
         .dsize = fiddle_ptr_memsize,
     },
-    .flags = RUBY_TYPED_FREE_IMMEDIATELY | RUBY_TYPED_WB_PROTECTED
+    .flags = FIDDLE_DEFAULT_TYPED_DATA_FALGS,
 };
 
 #ifdef HAVE_RUBY_MEMORY_VIEW_H
diff --git a/test/fiddle/helper.rb b/test/fiddle/helper.rb
index e470f5a2..cf4e41cf 100644
--- a/test/fiddle/helper.rb
+++ b/test/fiddle/helper.rb
@@ -180,5 +180,10 @@ def under_gc_stress
     ensure
       GC.stress = stress
     end
+
+    def assert_ractor_shareable(object)
+      Ractor.make_shareable(object)
+      assert_operator Ractor, :shareable?, object
+    end
   end
 end
diff --git a/test/fiddle/test_closure.rb b/test/fiddle/test_closure.rb
index abb6bdbd..0adf02d9 100644
--- a/test/fiddle/test_closure.rb
+++ b/test/fiddle/test_closure.rb
@@ -149,5 +149,11 @@ def test_memsize_ruby_dev_42480
         end
       end
     end
+
+    ractor def test_ractor_shareable
+      Closure.create(:int, [:void]) do |c|
+        assert_ractor_shareable(c)
+      end
+    end
   end
 end if defined?(Fiddle)
diff --git a/test/fiddle/test_function.rb b/test/fiddle/test_function.rb
index 847df379..9879a774 100644
--- a/test/fiddle/test_function.rb
+++ b/test/fiddle/test_function.rb
@@ -225,6 +225,10 @@ def test_no_memory_leak
       end
     end
 
+    ractor def test_ractor_shareable
+      assert_ractor_shareable(Function.new(@libm['sin'], [TYPE_DOUBLE], TYPE_DOUBLE))
+    end
+
     private
 
     def perror(m)
diff --git a/test/fiddle/test_handle.rb b/test/fiddle/test_handle.rb
index 412c10e0..764f6069 100644
--- a/test/fiddle/test_handle.rb
+++ b/test/fiddle/test_handle.rb
@@ -214,5 +214,9 @@ def test_fallback_to_ansi
         assert_equal(ansi, k["GetFileAttributes"], "should fallback to ANSI version")
       end
     end
+
+    ractor def test_ractor_shareable
+      assert_ractor_shareable(Fiddle::Handle.new(LIBC_SO))
+    end
   end
 end if defined?(Fiddle)
diff --git a/test/fiddle/test_memory_view.rb b/test/fiddle/test_memory_view.rb
index 240cda37..bd45f405 100644
--- a/test/fiddle/test_memory_view.rb
+++ b/test/fiddle/test_memory_view.rb
@@ -139,5 +139,11 @@ def test_to_s
       assert_equal([data.b, true],
                    [string, string.frozen?])
     end
+
+    ractor def test_ractor_shareable
+      ptr = Pointer["hello world"]
+      assert_ractor_shareable MemoryView.new(ptr)
+      assert_predicate ptr, :frozen?
+    end
   end
 end
diff --git a/test/fiddle/test_pinned.rb b/test/fiddle/test_pinned.rb
index f0d375b1..93deaf8c 100644
--- a/test/fiddle/test_pinned.rb
+++ b/test/fiddle/test_pinned.rb
@@ -23,6 +23,11 @@ def test_clear
       end
       assert_match "called on", ex.message
     end
+
+    ractor def test_ractor_shareable
+      obj = Object.new
+      assert_ractor_shareable(Pinned.new(obj))
+      assert_predicate obj, :frozen?
+    end
   end
 end
-
diff --git a/test/fiddle/test_pointer.rb b/test/fiddle/test_pointer.rb
index f2c1d285..68197b41 100644
--- a/test/fiddle/test_pointer.rb
+++ b/test/fiddle/test_pointer.rb
@@ -302,5 +302,12 @@ def test_no_memory_leak
         assert_no_memory_leak(%w[-W0 -rfiddle.so], '', '100_000.times {Fiddle::Pointer.allocate}', rss: true)
       end
     end
+
+    ractor def test_ractor_shareable
+      assert_ractor_shareable(Fiddle::NULL)
+      ary = [0,1,2,4,5]
+      addr = Pointer.new(dlwrap(ary))
+      assert_ractor_shareable(addr)
+    end
   end
 end if defined?(Fiddle)