diff --git a/tmux.1 b/tmux.1
index cba38264..8fa6ad55 100644
--- a/tmux.1
+++ b/tmux.1
@@ -3413,6 +3413,7 @@ The following variables are available, where appropriate:
 .It Li "session_name" Ta "#S" Ta "Name of session"
 .It Li "session_width" Ta "" Ta "Width of session"
 .It Li "session_windows" Ta "" Ta "Number of windows in session"
+.It Li "socket_path" Ta "" "Server socket path"
 .It Li "start_time" Ta "" Ta "Server start time"
 .It Li "window_activity" Ta "" Ta "Integer time of window last activity"
 .It Li "window_active" Ta "" Ta "1 if window active"