diff --git a/gems/cgi/0.5/_test/test.rb b/gems/cgi/0.5/_test/test.rb
index 7fec9c5b..a24da7bb 100644
--- a/gems/cgi/0.5/_test/test.rb
+++ b/gems/cgi/0.5/_test/test.rb
@@ -5,4 +5,29 @@
 cgi = CGI.new
 cgi.out("text/plain") { "string" }
 
+CGI.escape("'Stop!' said Fred") #=> "%27Stop%21%27+said+Fred"
+CGI.unescape("%27Stop%21%27+said+Fred")  #=> "'Stop!' said Fred"
+
+CGI.escapeURIComponent("'Stop!' said Fred") #=> "%27Stop%21%27%20said%20Fred"
+CGI.escape_uri_component("'Stop!' said Fred") #=> "%27Stop%21%27%20said%20Fred"
+
+CGI.unescapeURIComponent("%27Stop%21%27+said%20Fred") #=> "'Stop!'+said Fred"
+CGI.unescape_uri_component("%27Stop%21%27+said%20Fred") #=> "'Stop!'+said Fred"
+
+CGI.escapeHTML('Usage: foo "bar" <baz>') #=> "Usage: foo &quot;bar&quot; &lt;baz&gt;"
+CGI.escape_html('Usage: foo "bar" <baz>') #=> "Usage: foo &quot;bar&quot; &lt;baz&gt;"
+
+CGI.unescapeHTML("Usage: foo &quot;bar&quot; &lt;baz&gt;") #=> "Usage: foo \"bar\" <baz>"
+CGI.unescape_html("Usage: foo &quot;bar&quot; &lt;baz&gt;") #=> "Usage: foo \"bar\" <baz>"
+
+CGI.escapeElement('<BR><A HREF="url"></A>', "A", "IMG") #=> "<BR>&lt;A HREF=&quot;url&quot;&gt;&lt;/A&gt"
+CGI.escapeElement('<BR><A HREF="url"></A>', ["A", "IMG"]) #=> "<BR>&lt;A HREF=&quot;url&quot;&gt;&lt;/A&gt"
+CGI.escape_element('<BR><A HREF="url"></A>', "A", "IMG") #=> "<BR>&lt;A HREF=&quot;url&quot;&gt;&lt;/A&gt"
+CGI.escape_element('<BR><A HREF="url"></A>', ["A", "IMG"]) #=> "<BR>&lt;A HREF=&quot;url&quot;&gt;&lt;/A&gt"
+
+CGI.unescapeElement("<BR>&lt;A HREF=&quot;url&quot;&gt;&lt;/A&gt", "A", "IMG") #=> "<BR><A HREF=\"url\"></A&gt"
+CGI.unescapeElement("&lt;BR&gt;&lt;A HREF=&quot;url&quot;&gt;&lt;/A&gt;", ["A", "IMG"]) #=> "&lt;BR&gt;<A HREF=\"url\"></A>"
+CGI.unescape_element("<BR>&lt;A HREF=&quot;url&quot;&gt;&lt;/A&gt", "A", "IMG") #=> "<BR><A HREF=\"url\"></A&gt"
+CGI.unescape_element("&lt;BR&gt;&lt;A HREF=&quot;url&quot;&gt;&lt;/A&gt;", ["A", "IMG"]) #=> "&lt;BR&gt;<A HREF=\"url\"></A>"
+
 cookies = CGI::Cookie.parse("raw_cookie_string")
diff --git a/gems/cgi/0.5/core.rbs b/gems/cgi/0.5/core.rbs
index 4c563f0d..2c16f01e 100644
--- a/gems/cgi/0.5/core.rbs
+++ b/gems/cgi/0.5/core.rbs
@@ -887,6 +887,26 @@ class CGI
     #
     def rfc1123_date: (Time time) -> String
 
+    def escape: (String) -> String
+    def unescape: (String, ?encoding: Encoding) -> String
+
+    def escapeURIComponent: (String) -> String
+    def unescapeURIComponent: (String, ?encoding: Encoding) -> String
+    alias escape_uri_component escapeURIComponent
+    alias unescape_uri_component unescapeURIComponent
+
+    def escapeHTML: (String) -> String
+    def unescapeHTML: (String) -> String
+    alias escape_html escapeHTML
+    alias unescape_html unescapeHTML
+
+    def escapeElement: (String, *String) -> String
+                     | (String, Array[String]) -> String
+    def unescapeElement: (String, *String) -> String
+                       | (String, Array[String]) -> String
+    alias escape_element escapeElement
+    alias unescape_element unescapeElement
+
     # Abbreviated day-of-week names specified by RFC 822
     RFC822_DAYS: Array[String]