diff --git a/check-version.sh b/check-version.sh
new file mode 100755
index 0000000..d69a23e
--- /dev/null
+++ b/check-version.sh
@@ -0,0 +1,96 @@
+#!/usr/bin/env bash
+
+# Compare the current tmux version against a given version.
+# Exit: 0 if comparison is true, 1 if false
+
+set -euo pipefail
+
+usage() {
+  echo "usage: $0 <operator> <version>" >&2
+  echo "operators: < <= == >= >" >&2
+}
+
+if [[ ${1:-} == "-h" || ${1:-} == "--help" ]]; then
+  usage
+  exit 0
+fi
+
+if [[ $# -ne 2 ]]; then
+  usage
+  exit 1
+fi
+
+operator="$1"
+target_version="$2"
+
+# Extract tmux version (e.g., "tmux 3.3a" -> "3.3a")
+current_version=$(tmux -V | sed 's/^tmux //')
+
+# Compare two version strings
+# Returns: -1 if v1 < v2, 0 if v1 == v2, 1 if v1 > v2
+compare_versions() {
+  local v1="$1"
+  local v2="$2"
+
+  # Strip trailing letters (e.g., "3.3a" -> "3.3") and save them
+  local v1_suffix="${v1##*[0-9]}"
+  local v2_suffix="${v2##*[0-9]}"
+  v1="${v1%[a-zA-Z]*}"
+  v2="${v2%[a-zA-Z]*}"
+
+  # Split into components
+  IFS='.' read -ra v1_parts <<< "$v1"
+  IFS='.' read -ra v2_parts <<< "$v2"
+
+  # Compare numeric parts
+  local max_len=$(( ${#v1_parts[@]} > ${#v2_parts[@]} ? ${#v1_parts[@]} : ${#v2_parts[@]} ))
+  for ((i = 0; i < max_len; i++)); do
+    local p1="${v1_parts[i]:-0}"
+    local p2="${v2_parts[i]:-0}"
+    if ((p1 < p2)); then
+      echo -1
+      return
+    elif ((p1 > p2)); then
+      echo 1
+      return
+    fi
+  done
+
+  # Numeric parts equal, compare suffixes (no suffix < a < b < ...)
+  # A letter suffix indicates a patch release, so 3.6a > 3.6
+  if [[ -z "$v1_suffix" && -n "$v2_suffix" ]]; then
+    echo -1
+    return
+  elif [[ -n "$v1_suffix" && -z "$v2_suffix" ]]; then
+    echo 1
+    return
+  elif [[ "$v1_suffix" < "$v2_suffix" ]]; then
+    echo -1
+    return
+  elif [[ "$v1_suffix" > "$v2_suffix" ]]; then
+    echo 1
+    return
+  fi
+
+  echo 0
+}
+
+result=$(compare_versions "$current_version" "$target_version")
+
+case "$operator" in
+  '<')
+    [[ "$result" -eq -1 ]] && exit 0 || exit 1 ;;
+  '<=')
+    [[ "$result" -le 0 ]] && exit 0 || exit 1 ;;
+  '==')
+    [[ "$result" -eq 0 ]] && exit 0 || exit 1 ;;
+  '>=')
+    [[ "$result" -ge 0 ]] && exit 0 || exit 1 ;;
+  '>')
+    [[ "$result" -eq 1 ]] && exit 0 || exit 1 ;;
+  *)
+    echo "error: invalid operator: $operator" >&2
+    usage
+    exit 1
+    ;;
+esac
diff --git a/tmux.conf b/tmux.conf
index bb04aeb..11c7fac 100644
--- a/tmux.conf
+++ b/tmux.conf
@@ -28,7 +28,7 @@ set -g status-interval 2
 set -g default-terminal "tmux-256color"
 
 # Enable true-color
-if '[[ "$TMUX_VERSION" < "3.2" ]]' \
+if '~/.config/tmux/check-version.sh "<" 3.2' \
   'set-option -as terminal-features ",xterm*:Tc"' \
   'set-option -as terminal-features ",xterm*:RGB"'
 
@@ -49,7 +49,7 @@ unbind -T copy-mode-vi MouseDragEnd1Pane
 # Enable changing cursor shape per pane, vim or zsh should emit escape
 # sequences to change cursor shape.
 # iTerm2 only requires this before tmux 2.9
-if '[ -n $ITERM_PROFILE ] && [[ "$TMUX_VERSION" < "2.9" ]]' \
+if '[ -n $ITERM_PROFILE ] && ~/.config/tmux/check-version.sh "<" 2.9' \
   'set -ga terminal-overrides "*:Ss=\E]1337;CursorShape=%p1%d\7"'
 # VTE compatible terminals.
 if '[ ! -n $ITERM_PROFILE ]' \
@@ -66,7 +66,7 @@ bind a run-shell ~/.local/share/tmux/layouts/window-auto
 if -b '[ "`uname`" = "Darwin" ]' \
   'set -g default-command "reattach-to-user-namespace -l $SHELL"'
 
-if -b '[[ "$TMUX_VERSION" > "3.2" ]]' {
+if -b '~/.config/tmux/check-version.sh ">" 3.2' {
   # Open a popup with running the default shell
   bind T display-popup -S fg=#54546D -b rounded -d '#{pane_current_path}' -E $SHELL
   # Open a popup with session creator/switcher