diff --git a/test/fixtures/configuration/default.yml b/test/fixtures/configuration/default.yml.txt
similarity index 100%
rename from test/fixtures/configuration/default.yml
rename to test/fixtures/configuration/default.yml.txt
diff --git a/test/fixtures/configuration/empty.yml b/test/fixtures/configuration/empty.yml.txt
similarity index 100%
rename from test/fixtures/configuration/empty.yml
rename to test/fixtures/configuration/empty.yml.txt
diff --git a/test/fixtures/configuration/no_default.yml b/test/fixtures/configuration/no_default.yml.txt
similarity index 100%
rename from test/fixtures/configuration/no_default.yml
rename to test/fixtures/configuration/no_default.yml.txt
diff --git a/test/fixtures/configuration/overrides.yml b/test/fixtures/configuration/overrides.yml.txt
similarity index 100%
rename from test/fixtures/configuration/overrides.yml
rename to test/fixtures/configuration/overrides.yml.txt
diff --git a/test/unit/lib/redmine/configuration_test.rb b/test/unit/lib/redmine/configuration_test.rb
index 896f4f1ce..cd3d95845 100644
--- a/test/unit/lib/redmine/configuration_test.rb
+++ b/test/unit/lib/redmine/configuration_test.rb
@@ -23,26 +23,26 @@ class Redmine::ConfigurationTest < ActiveSupport::TestCase
   end
 
   def test_empty
-    assert_kind_of Hash, load_conf('empty.yml', 'test')
+    assert_kind_of Hash, load_conf('empty.yml.txt', 'test')
   end
 
   def test_default
-    assert_kind_of Hash, load_conf('default.yml', 'test')
+    assert_kind_of Hash, load_conf('default.yml.txt', 'test')
     assert_equal 'foo', @conf['somesetting']
   end
 
   def test_no_default
-    assert_kind_of Hash, load_conf('no_default.yml', 'test')
+    assert_kind_of Hash, load_conf('no_default.yml.txt', 'test')
     assert_equal 'foo', @conf['somesetting']
   end
 
   def test_overrides
-    assert_kind_of Hash, load_conf('overrides.yml', 'test')
+    assert_kind_of Hash, load_conf('overrides.yml.txt', 'test')
     assert_equal 'bar', @conf['somesetting']
   end
 
   def test_with
-    load_conf('default.yml', 'test')
+    load_conf('default.yml.txt', 'test')
     assert_equal 'foo', @conf['somesetting']
     @conf.with 'somesetting' => 'bar' do
       assert_equal 'bar', @conf['somesetting']