diff --git a/doc/configuration.txt b/doc/configuration.txt
index aa0062885..a4276f569 100644
--- a/doc/configuration.txt
+++ b/doc/configuration.txt
@@ -2190,6 +2190,12 @@ bind /<path> [, ...] [param*]
         listen external_bind_app1
             bind "fd@${FD_APP1}"
 
+  Note: regarding Linux's abstract namespace sockets, HAProxy uses the whole
+        sun_path length is used for the address length. Some other programs
+        such as socat use the string length only by default. Pass the option
+        ",unix-tightsocklen=0" to any abstract socket definition in socat to
+        make it compatible with HAProxy's.
+
   See also : "source", "option forwardfor", "unix-bind" and the PROXY protocol
              documentation, and section 5 about bind options.
 
@@ -6988,6 +6994,12 @@ server <name> <address>[:[port]] [param*]
         server www1_dc1 "${LAN_DC1}.101:80"
         server www1_dc2 "${LAN_DC2}.101:80"
 
+  Note: regarding Linux's abstract namespace sockets, HAProxy uses the whole
+        sun_path length is used for the address length. Some other programs
+        such as socat use the string length only by default. Pass the option
+        ",unix-tightsocklen=0" to any abstract socket definition in socat to
+        make it compatible with HAProxy's.
+
   See also: "default-server", "http-send-name-header" and section 5 about
              server options