diff --git a/lib/net/imap/response_data.rb b/lib/net/imap/response_data.rb
index 16ff306ce..40586ebde 100644
--- a/lib/net/imap/response_data.rb
+++ b/lib/net/imap/response_data.rb
@@ -7,6 +7,7 @@ class IMAP < Protocol
     autoload :UIDFetchData,     "#{__dir__}/fetch_data"
     autoload :SearchResult,     "#{__dir__}/search_result"
     autoload :SequenceSet,      "#{__dir__}/sequence_set"
+    autoload :UIDPlusData,      "#{__dir__}/uidplus_data"
     autoload :VanishedData,     "#{__dir__}/vanished_data"
 
     # Net::IMAP::ContinuationRequest represents command continuation requests.
@@ -344,55 +345,6 @@ class ResponseCode < Struct.new(:name, :data)
       # code data can take.
     end
 
-    # UIDPlusData represents the ResponseCode#data that accompanies the
-    # +APPENDUID+ and +COPYUID+ {response codes}[rdoc-ref:ResponseCode].
-    #
-    # A server that supports +UIDPLUS+ should send a UIDPlusData object inside
-    # every TaggedResponse returned by the append[rdoc-ref:Net::IMAP#append],
-    # copy[rdoc-ref:Net::IMAP#copy], move[rdoc-ref:Net::IMAP#move], {uid
-    # copy}[rdoc-ref:Net::IMAP#uid_copy], and {uid
-    # move}[rdoc-ref:Net::IMAP#uid_move] commands---unless the destination
-    # mailbox reports +UIDNOTSTICKY+.
-    #
-    # == Required capability
-    # Requires either +UIDPLUS+ [RFC4315[https://www.rfc-editor.org/rfc/rfc4315]]
-    # or +IMAP4rev2+ capability.
-    #
-    class UIDPlusData < Struct.new(:uidvalidity, :source_uids, :assigned_uids)
-      ##
-      # method: uidvalidity
-      # :call-seq: uidvalidity -> nonzero uint32
-      #
-      # The UIDVALIDITY of the destination mailbox.
-
-      ##
-      # method: source_uids
-      # :call-seq: source_uids -> nil or an array of nonzero uint32
-      #
-      # The UIDs of the copied or moved messages.
-      #
-      # Note:: Returns +nil+ for Net::IMAP#append.
-
-      ##
-      # method: assigned_uids
-      # :call-seq: assigned_uids -> an array of nonzero uint32
-      #
-      # The newly assigned UIDs of the copied, moved, or appended messages.
-      #
-      # Note:: This always returns an array, even when it contains only one UID.
-
-      ##
-      # :call-seq: uid_mapping -> nil or a hash
-      #
-      # Returns a hash mapping each source UID to the newly assigned destination
-      # UID.
-      #
-      # Note:: Returns +nil+ for Net::IMAP#append.
-      def uid_mapping
-        source_uids&.zip(assigned_uids)&.to_h
-      end
-    end
-
     # MailboxList represents the data of an untagged +LIST+ response, for a
     # _single_ mailbox path.  IMAP#list returns an array of MailboxList objects.
     #
diff --git a/lib/net/imap/uidplus_data.rb b/lib/net/imap/uidplus_data.rb
new file mode 100644
index 000000000..2c478e2c9
--- /dev/null
+++ b/lib/net/imap/uidplus_data.rb
@@ -0,0 +1,56 @@
+# frozen_string_literal: true
+
+module Net
+  class IMAP < Protocol
+
+    # UIDPlusData represents the ResponseCode#data that accompanies the
+    # +APPENDUID+ and +COPYUID+ {response codes}[rdoc-ref:ResponseCode].
+    #
+    # A server that supports +UIDPLUS+ should send a UIDPlusData object inside
+    # every TaggedResponse returned by the append[rdoc-ref:Net::IMAP#append],
+    # copy[rdoc-ref:Net::IMAP#copy], move[rdoc-ref:Net::IMAP#move], {uid
+    # copy}[rdoc-ref:Net::IMAP#uid_copy], and {uid
+    # move}[rdoc-ref:Net::IMAP#uid_move] commands---unless the destination
+    # mailbox reports +UIDNOTSTICKY+.
+    #
+    # == Required capability
+    # Requires either +UIDPLUS+ [RFC4315[https://www.rfc-editor.org/rfc/rfc4315]]
+    # or +IMAP4rev2+ capability.
+    #
+    class UIDPlusData < Struct.new(:uidvalidity, :source_uids, :assigned_uids)
+      ##
+      # method: uidvalidity
+      # :call-seq: uidvalidity -> nonzero uint32
+      #
+      # The UIDVALIDITY of the destination mailbox.
+
+      ##
+      # method: source_uids
+      # :call-seq: source_uids -> nil or an array of nonzero uint32
+      #
+      # The UIDs of the copied or moved messages.
+      #
+      # Note:: Returns +nil+ for Net::IMAP#append.
+
+      ##
+      # method: assigned_uids
+      # :call-seq: assigned_uids -> an array of nonzero uint32
+      #
+      # The newly assigned UIDs of the copied, moved, or appended messages.
+      #
+      # Note:: This always returns an array, even when it contains only one UID.
+
+      ##
+      # :call-seq: uid_mapping -> nil or a hash
+      #
+      # Returns a hash mapping each source UID to the newly assigned destination
+      # UID.
+      #
+      # Note:: Returns +nil+ for Net::IMAP#append.
+      def uid_mapping
+        source_uids&.zip(assigned_uids)&.to_h
+      end
+    end
+
+  end
+end