diff --git a/test/rdoc/support/text_formatter_test_case.rb b/test/rdoc/support/text_formatter_test_case.rb
index 9b3d7ed626..5a51b16fd7 100644
--- a/test/rdoc/support/text_formatter_test_case.rb
+++ b/test/rdoc/support/text_formatter_test_case.rb
@@ -103,13 +103,13 @@ def test_accept_paragraph_wrap
       # Test case that calls <tt>@to.accept_table</tt>
 
       def test_accept_table_align
-        header = ['AA', 'BB', 'CCCCC']
+        header = ['AA', 'BB', 'CCCCC', 'DDDDD']
         body = [
-          ['', 'bbb', 'c'],
-          ['aaaa', 'b', ''],
-          ['a', '', 'cc']
+          ['', 'bbb', 'c', ''],
+          ['aaaa', 'b', '', 'dd'],
+          ['a', '', 'cc', 'dd']
         ]
-        aligns = [nil, :left, :right]
+        aligns = [nil, :left, :right, :center]
         @to.start_accepting
         @to.accept_table header, body, aligns
 
diff --git a/test/rdoc/test_rdoc_markup_to_ansi.rb b/test/rdoc/test_rdoc_markup_to_ansi.rb
index 893040cb44..020f546997 100644
--- a/test/rdoc/test_rdoc_markup_to_ansi.rb
+++ b/test/rdoc/test_rdoc_markup_to_ansi.rb
@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 require_relative 'helper'
 
-class TestRDocMarkupToAnsi < RDoc::Markup::TextFormatterTestCase
+class RDocMarkupToAnsiTest < RDoc::Markup::TextFormatterTestCase
 
   add_visitor_tests
   add_text_tests
@@ -350,11 +350,11 @@ def list_verbatim
 
   def accept_table_align
     expected = "\e[0m" + <<-EXPECTED
- AA |BB |CCCCC
-----|---|-----
-    |bbb|    c
-aaaa|b  |
- a  |   |   cc
+ AA |BB |CCCCC|DDDDD
+----|---|-----|-----
+    |bbb|    c|
+aaaa|b  |     | dd
+ a  |   |   cc| dd
     EXPECTED
     assert_equal expected, @to.end_accepting
   end
diff --git a/test/rdoc/test_rdoc_markup_to_bs.rb b/test/rdoc/test_rdoc_markup_to_bs.rb
index 93baa6b59f..d89d784422 100644
--- a/test/rdoc/test_rdoc_markup_to_bs.rb
+++ b/test/rdoc/test_rdoc_markup_to_bs.rb
@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 require_relative 'helper'
 
-class TestRDocMarkupToBs < RDoc::Markup::TextFormatterTestCase
+class RDocMarkupToBsTest < RDoc::Markup::TextFormatterTestCase
 
   add_visitor_tests
   add_text_tests
@@ -351,11 +351,11 @@ def list_verbatim
 
   def accept_table_align
     expected = <<-EXPECTED
- AA |BB |CCCCC
-----|---|-----
-    |bbb|    c
-aaaa|b  |
- a  |   |   cc
+ AA |BB |CCCCC|DDDDD
+----|---|-----|-----
+    |bbb|    c|
+aaaa|b  |     | dd
+ a  |   |   cc| dd
     EXPECTED
     assert_equal expected, @to.end_accepting
   end
diff --git a/test/rdoc/test_rdoc_markup_to_html.rb b/test/rdoc/test_rdoc_markup_to_html.rb
index 225598a651..ffd16f0837 100644
--- a/test/rdoc/test_rdoc_markup_to_html.rb
+++ b/test/rdoc/test_rdoc_markup_to_html.rb
@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 require_relative 'helper'
 
-class TestRDocMarkupToHtml < RDoc::Markup::FormatterTestCase
+class RDocMarkupToHtmlTest < RDoc::Markup::FormatterTestCase
 
   add_visitor_tests
 
@@ -956,31 +956,34 @@ def util_format text
   end
 
   def test_accept_table
-    header = %w[Col1 Col2 Col3]
+    header = %w[Col1 Col2 Col3 Col4]
     body = [
-      %w[cell1_1 cell1_2 cell1_3],
-      %w[cell2_1 cell2_2 cell2_3],
-      ['<script>alert("foo");</script>',],
-      %w[+code+ _em_ **strong**],
+      %w[cell1_1 cell1_2 cell1_3 cell1_4],
+      %w[cell2_1 cell2_2 cell2_3 cell2_4],
+      ['<script>alert("foo");</script>'],
+      %w[+code+ _em_ **strong** C1],
     ]
-    aligns = [:left, :right, nil]
+    aligns = [:left, :right, nil, :center]
     @to.start_accepting
     @to.accept_table(header, body, aligns)
     res = @to.end_accepting
     assert_include(res[%r<<th[^<>]*>Col1</th>>], 'align="left"')
     assert_include(res[%r<<th[^<>]*>Col2</th>>], 'align="right"')
     assert_not_include(res[%r<<th[^<>]*>Col3</th>>], 'align=')
+    assert_include(res[%r<<th[^<>]*>Col4</th>>], 'align="center"')
     assert_include(res[%r<<td[^<>]*>cell1_1</td>>], 'align="left"')
     assert_include(res[%r<<td[^<>]*>cell1_2</td>>], 'align="right"')
     assert_not_include(res[%r<<td[^<>]*>cell1_3</td>>], 'align=')
     assert_include(res[%r<<td[^<>]*>cell2_1</td>>], 'align="left"')
     assert_include(res[%r<<td[^<>]*>cell2_2</td>>], 'align="right"')
     assert_not_include(res[%r<<td[^<>]*>cell2_3</td>>], 'align=')
+    assert_include(res[%r<<td[^<>]*>cell2_4</td>>], 'align="center"')
     assert_not_include(res, '<script>')
     assert_include(res[%r<<td[^<>]*>.*script.*</td>>], '&lt;script&gt;')
     assert_include(res[%r<<td[^<>]*>.*code.*</td>>], '<code>code</code>')
     assert_include(res[%r<<td[^<>]*>.*em.*</td>>], '<em>em</em>')
     assert_include(res[%r<<td[^<>]*>.*strong.*</td>>], '<strong>strong</strong>')
+    assert_include(res[%r<<td[^<>]*>C1</td>>], 'C1')
   end
 
   def assert_escaped(unexpected, code)
diff --git a/test/rdoc/test_rdoc_markup_to_markdown.rb b/test/rdoc/test_rdoc_markup_to_markdown.rb
index 1b24eb8ef0..86fe5ce82b 100644
--- a/test/rdoc/test_rdoc_markup_to_markdown.rb
+++ b/test/rdoc/test_rdoc_markup_to_markdown.rb
@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 require_relative 'helper'
 
-class TestRDocMarkupToMarkdown < RDoc::Markup::TextFormatterTestCase
+class RDocMarkupToMarkdownTest < RDoc::Markup::TextFormatterTestCase
 
   add_visitor_tests
   add_text_tests
@@ -348,11 +348,11 @@ def list_verbatim
 
   def accept_table_align
     expected = <<-EXPECTED
- AA |BB |CCCCC
-----|---|-----
-    |bbb|    c
-aaaa|b  |
- a  |   |   cc
+ AA |BB |CCCCC|DDDDD
+----|---|-----|-----
+    |bbb|    c|
+aaaa|b  |     | dd
+ a  |   |   cc| dd
     EXPECTED
     assert_equal expected, @to.end_accepting
   end
diff --git a/test/rdoc/test_rdoc_markup_to_rdoc.rb b/test/rdoc/test_rdoc_markup_to_rdoc.rb
index c6f1aeae10..c7d6120c0d 100644
--- a/test/rdoc/test_rdoc_markup_to_rdoc.rb
+++ b/test/rdoc/test_rdoc_markup_to_rdoc.rb
@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 require_relative 'helper'
 
-class TestRDocMarkupToRDoc < RDoc::Markup::TextFormatterTestCase
+class RDocMarkupToRDocTest < RDoc::Markup::TextFormatterTestCase
 
   add_visitor_tests
   add_text_tests
@@ -348,11 +348,11 @@ def list_verbatim
 
   def accept_table_align
     expected = <<-EXPECTED
- AA |BB |CCCCC
-----|---|-----
-    |bbb|    c
-aaaa|b  |
- a  |   |   cc
+ AA |BB |CCCCC|DDDDD
+----|---|-----|-----
+    |bbb|    c|
+aaaa|b  |     | dd
+ a  |   |   cc| dd
     EXPECTED
     assert_equal expected, @to.end_accepting
   end