diff --git a/lib/net/imap/config/attr_accessors.rb b/lib/net/imap/config/attr_accessors.rb
index cef757e0..609da208 100644
--- a/lib/net/imap/config/attr_accessors.rb
+++ b/lib/net/imap/config/attr_accessors.rb
@@ -58,9 +58,9 @@ def freeze
 
         private
 
-        def initialize_clone(other)
+        def initialize_clone(other, **kwargs)
           super
-          @data = other.data.clone
+          @data = other.data.clone(**kwargs)
         end
 
         def initialize_dup(other)
diff --git a/lib/net/imap/sequence_set.rb b/lib/net/imap/sequence_set.rb
index a5dabfc7..b12461b3 100644
--- a/lib/net/imap/sequence_set.rb
+++ b/lib/net/imap/sequence_set.rb
@@ -1869,8 +1869,9 @@ def remain_frozen(set) frozen? ? set.freeze : set end
       def remain_frozen_empty; frozen? ? SequenceSet.empty : SequenceSet.new end
 
       # frozen clones are shallow copied
-      def initialize_clone(other)
-        @set_data = other.dup_set_data unless other.frozen?
+      def initialize_clone(other, freeze: nil)
+        @set_data = other.dup_set_data unless other.frozen? && freeze != false
+        freeze_set_data if freeze
         super
       end
 
diff --git a/test/net/imap/test_config.rb b/test/net/imap/test_config.rb
index 5c03adf6..4abb5350 100644
--- a/test/net/imap/test_config.rb
+++ b/test/net/imap/test_config.rb
@@ -312,6 +312,21 @@ def duck.to_r   = 1/11111
     assert_equal 1, copy.open_timeout
   end
 
+  test "#clone(freeze:)" do
+    original = Config.new(open_timeout: 1).freeze
+    copy = original.clone(freeze: false)
+    refute copy.frozen?
+    copy.open_timeout = 2
+    assert_equal 1, original.open_timeout
+    assert_equal 2, copy.open_timeout
+
+    copy = Config.new(open_timeout: 1).clone(freeze: true)
+    assert copy.frozen?
+    assert_raise FrozenError do
+      copy.open_timeout = 2
+    end
+  end
+
   test "#inherited? and #reset" do
     base = Config.new debug: false, open_timeout: 99, idle_response_timeout: 15
     child = base.new debug: true, open_timeout: 15, idle_response_timeout: 10
diff --git a/test/net/imap/test_sequence_set.rb b/test/net/imap/test_sequence_set.rb
index fd6efa12..a3131047 100644
--- a/test/net/imap/test_sequence_set.rb
+++ b/test/net/imap/test_sequence_set.rb
@@ -233,6 +233,21 @@ def compare_to_reference_set(nums, set, seqset)
     end
   end
 
+  test "#clone(freeze:)" do
+    original = SequenceSet["2:4,7:11,99,999"]
+    copy = original.clone(freeze: false)
+    refute copy.frozen?
+    copy << 123
+    assert copy.include?(123)
+    assert !original.include?(123)
+
+    copy = SequenceSet.new("2:4,7:11,99,999").clone(freeze: true)
+    assert copy.frozen?
+    assert_raise FrozenError do
+      copy << 123
+    end
+  end
+
   if defined?(Ractor)
     test "#freeze makes ractor sharable (deeply frozen)" do
       assert Ractor.shareable? SequenceSet.new("1:9,99,999").freeze