diff --git a/lib/cgi/escape.rb b/lib/cgi/escape.rb
index bdcdcdf..3385ffb 100644
--- a/lib/cgi/escape.rb
+++ b/lib/cgi/escape.rb
@@ -234,6 +234,6 @@ def unescapeElement(string, *elements)
 
   # Like StringValue in C
   def string_value(input)  # :nodoc:
-    String.try_convert(input) || raise(TypeError, "no implicit conversion of #{input.class} into String")
+    String === input ? input : "" + input
   end
 end
diff --git a/test/cgi/test_cgi_escape.rb b/test/cgi/test_cgi_escape.rb
index 3278bde..e0c2179 100644
--- a/test/cgi/test_cgi_escape.rb
+++ b/test/cgi/test_cgi_escape.rb
@@ -404,6 +404,14 @@ def teardown
     end if defined?(CGI::EscapeExt) and CGI::EscapeExt.method_defined?(:_escapeHTML)
   end
 
+  def test_escapeHTML_type_error_matches_c_extension
+    assert_raise_with_message(TypeError, "no implicit conversion of nil into String")   { CGI.escapeHTML(nil) }
+    assert_raise_with_message(TypeError, "no implicit conversion of true into String")  { CGI.escapeHTML(true) }
+    assert_raise_with_message(TypeError, "no implicit conversion of false into String") { CGI.escapeHTML(false) }
+    assert_raise_with_message(TypeError, "no implicit conversion of nil into String")   { CGI.unescapeHTML(nil) }
+    assert_raise(TypeError) { CGI.escapeHTML(BasicObject.new) }
+  end
+
   include CGIEscapeTest::UnescapeHTMLTests
 
   def test_cgi_escapeHTML_with_invalid_byte_sequence