diff --git a/lib/irb/extend-command.rb b/lib/irb/extend-command.rb
index 6446c48ef..5020b1e5c 100644
--- a/lib/irb/extend-command.rb
+++ b/lib/irb/extend-command.rb
@@ -259,8 +259,8 @@ def self.def_extend_command(cmd_name, cmd_class, load_file = nil, *aliases)
         kwargs = ", **kwargs" if RUBY_ENGINE == "ruby" && RUBY_VERSION >= "2.7.0"
         line = __LINE__; eval %[
           def #{cmd_name}(*opts#{kwargs}, &b)
-            require_relative "#{load_file}"
-            arity = ExtendCommand::#{cmd_class}.instance_method(:execute).arity
+            Kernel.require_relative "#{load_file}"
+            arity = ::IRB::ExtendCommand::#{cmd_class}.instance_method(:execute).arity
             args = (1..(arity < 0 ? ~arity : arity)).map {|i| "arg" + i.to_s }
             args << "*opts#{kwargs}" if arity < 0
             args << "&block"
@@ -269,7 +269,7 @@ def #{cmd_name}(*opts#{kwargs}, &b)
               unless singleton_class.class_variable_defined?(:@@#{cmd_name}_)
                 singleton_class.class_variable_set(:@@#{cmd_name}_, true)
                 def self.#{cmd_name}_(\#{args})
-                  ExtendCommand::#{cmd_class}.execute(irb_context, \#{args})
+                  ::IRB::ExtendCommand::#{cmd_class}.execute(irb_context, \#{args})
                 end
               end
             ], nil, __FILE__, line
@@ -279,7 +279,7 @@ def self.#{cmd_name}_(\#{args})
       else
         line = __LINE__; eval %[
           def #{cmd_name}(*opts, &b)
-            ExtendCommand::#{cmd_class}.execute(irb_context, *opts, &b)
+            ::IRB::ExtendCommand::#{cmd_class}.execute(irb_context, *opts, &b)
           end
         ], nil, __FILE__, line
       end
diff --git a/test/irb/test_cmd.rb b/test/irb/test_cmd.rb
index b909de56e..900d9d898 100644
--- a/test/irb/test_cmd.rb
+++ b/test/irb/test_cmd.rb
@@ -49,6 +49,19 @@ def execute_lines(*lines, conf: {}, main: self, irb_path: nil)
     end
   end
 
+  class FrozenObjectTest < CommandTestCase
+    def test_calling_command_on_a_frozen_main
+      main = Object.new.freeze
+
+      out, err = execute_lines(
+        "irb_info",
+        main: main
+      )
+      assert_empty err
+      assert_match(/RUBY_PLATFORM/, out)
+    end
+  end
+
   class CommnadAliasTest < CommandTestCase
     def test_vars_with_aliases
       @foo = "foo"