diff --git a/test/irb/helper.rb b/test/irb/helper.rb
index acaf6277f..ea2c6ef16 100644
--- a/test/irb/helper.rb
+++ b/test/irb/helper.rb
@@ -49,6 +49,19 @@ def ruby_core?
       !Pathname(__dir__).join("../../", "irb.gemspec").exist?
     end
 
+    def setup_envs(home:)
+      @backup_home = ENV["HOME"]
+      ENV["HOME"] = home
+      @backup_xdg_config_home = ENV.delete("XDG_CONFIG_HOME")
+      @backup_irbrc = ENV.delete("IRBRC")
+    end
+
+    def teardown_envs
+      ENV["HOME"] = @backup_home
+      ENV["XDG_CONFIG_HOME"] = @backup_xdg_config_home
+      ENV["IRBRC"] = @backup_irbrc
+    end
+
     def save_encodings
       @default_encoding = [Encoding.default_external, Encoding.default_internal]
       @stdio_encodings = [STDIN, STDOUT, STDERR].map {|io| [io.external_encoding, io.internal_encoding] }
diff --git a/test/irb/test_command.rb b/test/irb/test_command.rb
index 30c3f5ca2..567c3216c 100644
--- a/test/irb/test_command.rb
+++ b/test/irb/test_command.rb
@@ -15,9 +15,7 @@ def setup
         Dir.mkdir(@tmpdir)
       end
       Dir.chdir(@tmpdir)
-      @home_backup = ENV["HOME"]
-      ENV["HOME"] = @tmpdir
-      @xdg_config_home_backup = ENV.delete("XDG_CONFIG_HOME")
+      setup_envs(home: @tmpdir)
       save_encodings
       IRB.instance_variable_get(:@CONF).clear
       IRB.instance_variable_set(:@existing_rc_name_generators, nil)
@@ -25,8 +23,7 @@ def setup
     end
 
     def teardown
-      ENV["XDG_CONFIG_HOME"] = @xdg_config_home_backup
-      ENV["HOME"] = @home_backup
+      teardown_envs
       Dir.chdir(@pwd)
       FileUtils.rm_rf(@tmpdir)
       restore_encodings
diff --git a/test/irb/test_history.rb b/test/irb/test_history.rb
index 63be35fda..84f043892 100644
--- a/test/irb/test_history.rb
+++ b/test/irb/test_history.rb
@@ -12,19 +12,14 @@ class HistoryTest < TestCase
     def setup
       @original_verbose, $VERBOSE = $VERBOSE, nil
       @tmpdir = Dir.mktmpdir("test_irb_history_")
-      @backup_home = ENV["HOME"]
-      @backup_xdg_config_home = ENV.delete("XDG_CONFIG_HOME")
-      @backup_irbrc = ENV.delete("IRBRC")
+      setup_envs(home: @tmpdir)
       @backup_default_external = Encoding.default_external
-      ENV["HOME"] = @tmpdir
       IRB.instance_variable_set(:@existing_rc_name_generators, nil)
     end
 
     def teardown
       IRB.instance_variable_set(:@existing_rc_name_generators, nil)
-      ENV["HOME"] = @backup_home
-      ENV["XDG_CONFIG_HOME"] = @backup_xdg_config_home
-      ENV["IRBRC"] = @backup_irbrc
+      teardown_envs
       Encoding.default_external = @backup_default_external
       $VERBOSE = @original_verbose
       FileUtils.rm_rf(@tmpdir)
diff --git a/test/irb/test_init.rb b/test/irb/test_init.rb
index c423fa112..3e8d01c5c 100644
--- a/test/irb/test_init.rb
+++ b/test/irb/test_init.rb
@@ -270,17 +270,15 @@ def with_argv(argv)
 
   class ConfigValidationTest < TestCase
     def setup
-      @original_home = ENV["HOME"]
-      @original_irbrc = ENV["IRBRC"]
       # To prevent the test from using the user's .irbrc file
-      ENV["HOME"] = @home = Dir.mktmpdir
+      @home = Dir.mktmpdir
+      setup_envs(home: @home)
       super
     end
 
     def teardown
       super
-      ENV["IRBRC"] = @original_irbrc
-      ENV["HOME"] = @original_home
+      teardown_envs
       File.unlink(@irbrc)
       Dir.rmdir(@home)
       IRB.instance_variable_set(:@existing_rc_name_generators, nil)