diff --git a/History.rdoc b/History.rdoc
index 42d2a7283b..a295734a8a 100644
--- a/History.rdoc
+++ b/History.rdoc
@@ -21,6 +21,8 @@
   * RDoc better understands directives for comments.  Comment directives can
     now be found anywhere in multi-line comments.  Issue #90 by Ryan Davis
   * Tidy links to methods show the label again.  Issue #88 by Simon Chiang
+  * RDoc::Parser::C can now find comments directly above
+    +rb_define_class_under+.  Issue #89 by Enrico
 
 === 3.11 / 2011/10-17
 
diff --git a/lib/rdoc/parser/c.rb b/lib/rdoc/parser/c.rb
index 299873d6a3..df668e306a 100644
--- a/lib/rdoc/parser/c.rb
+++ b/lib/rdoc/parser/c.rb
@@ -572,6 +572,9 @@ def find_class_comment(class_name, class_mod)
     elsif @content =~ %r%((?>/\*.*?\*/\s+))
                          ([\w\.\s]+\s* = \s+)?rb_define_(class|module).*?"(#{class_name})"%xm then
       comment = $1
+    elsif @content =~ %r%((?>/\*.*?\*/\s+))
+                         ([\w\.\s]+\s* = \s+)?rb_define_(class|module)_under.*?"(#{class_name.split('::').last})"%xm then
+      comment = $1
     else
       comment = ''
     end
diff --git a/test/test_rdoc_parser_c.rb b/test/test_rdoc_parser_c.rb
index fac7481980..8f78e0a6f5 100644
--- a/test/test_rdoc_parser_c.rb
+++ b/test/test_rdoc_parser_c.rb
@@ -701,6 +701,41 @@ def test_find_class_comment_define_class_bogus_comment
     assert_equal '', klass.comment.text
   end
 
+  def test_find_class_comment_define_class_under
+    content = <<-EOF
+/*
+ * a comment for class Foo
+ */
+VALUE foo = rb_define_class_under(rb_cObject, "Foo", rb_cObject);
+    EOF
+
+    klass = util_get_class content, 'foo'
+
+    assert_equal "a comment for class Foo", klass.comment.text
+  end
+
+  def test_find_class_comment_define_class_under_Init
+    content = <<-EOF
+/*
+ * a comment for class Foo on Init
+ */
+void
+Init_Foo(void) {
+    /*
+     * a comment for class Foo on rb_define_class
+     */
+    VALUE foo = rb_define_class_under(rb_cObject, "Foo", rb_cObject);
+}
+    EOF
+
+    klass = util_get_class content, 'foo'
+
+    # the inner comment is used since Object::Foo is not necessarily the same
+    # thing as "Foo" for Init_
+    assert_equal "a comment for class Foo on rb_define_class",
+                 klass.comment.text
+  end
+
   def test_find_const_comment_rb_define
     content = <<-EOF
 /*