According to http://www.fastcgi.com/docs/faq.html#httpstatus

send the Status code, as an header line  Status: code reason

library/server/ewsgi/connectors/libfcgi/src/wgi_libfcgi_output_stream.e

@@ -42,8 +42,22 @@ feature -- Status writing
 			-- Put status code line for `a_code'
 			--| Note this is a default implementation, and could be redefined
 			--| for instance in relation to NPH CGI script
+		local
+			s: STRING
 		do
 			--| Do not send any Status line back to the FastCGI client
+			--| According to http://www.fastcgi.com/docs/faq.html#httpstatus
+			if a_code /= 200 then
+				create s.make (16)
+				s.append ("Status:")
+				s.append_character (' ')
+				s.append_integer (a_code)
+				if attached http_status_code_message (a_code) as l_status_message then
+					s.append_character (' ')
+					s.append_string (l_status_message)
+				end
+				put_header_line (s)
+			end
 		end
 
 feature -- Basic operation