--- a/rc/bashrc	Sun Jun 30 20:24:46 2019 +0900
+++ b/rc/bashrc	Sun Jun 30 20:25:30 2019 +0900
@@ -287,13 +287,17 @@
 
 if command -v tmux > /dev/null 2>&1; then
   case "${_os}" in
+  "OpenBSD "*" "6.[5-9]" "*|"OpenBSD "*" "[7-9].[0-9]" "*|"OpenBSD "*" "[1-9][0-9][0-9]*.[0-9]" "*)
+    _tmux_conf_ver=2.9
+  ;;
   OpenBSD)
-    # FIXME: OpenBSD version check
+    # probably not accurate enough but I don't want to dig through all the previous versions.
     _tmux_conf_ver=2.2
   ;;
   *)
     case "$(tmux -V 2> /dev/null)" in
-    "tmux 2."[2-9]|"tmux "[3-9]"."[0-9]|"tmux "[1-9][0-9][0.9]*"."[0-9]) _tmux_conf_ver=2.2;;
+    "tmux 2."[9][a-z]*|"tmux "[3-9]"."[0-9]|"tmux "[1-9][0-9][0.9]*"."[0-9]) _tmux_conf_ver=2.9;;
+    "tmux 2."[2-8]) _tmux_conf_ver=2.2;;
     "tmux 1.9"|"tmux 2."[0-1]) _tmux_conf_ver=1.9;;
     "tmux 1."[4-8]) _tmux_conf_ver=1.4;;
     *) _tmux_conf_ver=1.3;;