diff --git a/doc/proxy-protocol.txt b/doc/proxy-protocol.txt
index a2dbcea..a3925a4 100644
--- a/doc/proxy-protocol.txt
+++ b/doc/proxy-protocol.txt
@@ -692,6 +692,7 @@
     - thttpd 2.20c     : 400 Bad Request + abort => pass/optimal
     - mini-httpd-1.19  : 400 Bad Request + abort => pass/optimal
     - haproxy 1.4.21   : 400 Bad Request + abort => pass/optimal
+    - Squid 3          : 400 Bad Request + abort => pass/optimal
   - SSL :
     - stud 0.3.47      : connection abort        => pass/optimal
     - stunnel 4.45     : connection abort        => pass/optimal