diff --git a/assets/default/dotfiles/bash_alias b/assets/default/dotfiles/bash_alias
index 94572ce..3158fe6 100644
--- a/assets/default/dotfiles/bash_alias
+++ b/assets/default/dotfiles/bash_alias
@@ -10,3 +10,4 @@ alias tiga='tig --all'
 # cd
 alias cd..='cd ..'
 
+source $HOME/.bash_funcs
diff --git a/assets/default/dotfiles/bash_funcs b/assets/default/dotfiles/bash_funcs
new file mode 100644
index 0000000..3e88b6a
--- /dev/null
+++ b/assets/default/dotfiles/bash_funcs
@@ -0,0 +1,60 @@
+#! /bin/bash
+
+# Version compare based on
+# http://stackoverflow.com/questions/4023830/bash-how-compare-two-strings-in-version-format
+vercomp() {
+    if [[ $1 == $2 ]]
+    then
+        return 0
+    fi
+    local IFS=.
+    local i ver1=($1) ver2=($2)
+    # fill empty fields in ver1 with zeros
+    for ((i=${#ver1[@]}; i<${#ver2[@]}; i++))
+    do
+        ver1[i]=0
+    done
+    for ((i=0; i<${#ver1[@]}; i++))
+    do
+        if [[ -z ${ver2[i]} ]]
+        then
+            # fill empty fields in ver2 with zeros
+            ver2[i]=0
+        fi
+        if ((10#${ver1[i]} > 10#${ver2[i]}))
+        then
+            return 1
+        fi
+        if ((10#${ver1[i]} < 10#${ver2[i]}))
+        then
+            return 2
+        fi
+    done
+    return 0
+}
+
+vertest() {
+    local ver1=($1) op=($2) ver2=($3)
+    vercomp $ver1 $ver2
+    case $op in
+        '=')
+            [ $? -eq 0 ] && return 0 || return 1
+            ;;
+        '!=')
+            [ $? -ne 0 ] && return 0 || return 1
+            ;;
+        '<')
+            [ $? -eq 2 ] && return 0 || return 1
+            ;;
+        '<=')
+            [ $? -eq 2 -o $? -eq 0 ] && return 0 || return 1
+            ;;
+        '>')
+            [ $? -eq 1 ] && return 0 || return 1
+            ;;
+        '>=')
+            [ $? -eq 1 -o $? -eq 0 ] && return 0 || return 1
+            ;;
+    esac
+    return -1
+}
diff --git a/assets/default/dotfiles/tmux.conf b/assets/default/dotfiles/tmux.conf
index 469deaa..b0d5a3f 100644
--- a/assets/default/dotfiles/tmux.conf
+++ b/assets/default/dotfiles/tmux.conf
@@ -27,9 +27,13 @@ setw -g mouse-select-window on
 setw -g mouse-select-pane on
 
 # easy splitting
-bind | split-window -h -c "#{pane_current_path}"
-bind - split-window -c "#{pane_current_path}"
-bind _ split-window -c "#{pane_current_path}"
+if-shell "vertest `tmux -V` '>=' 1.9" 'bind | split-window -h -c "#{pane_current_path}"'
+if-shell "vertest `tmux -V` '>=' 1.9" 'bind - split-window -c "#{pane_current_path}"'
+if-shell "vertest `tmux -V` '>=' 1.9" 'bind _ split-window -c "#{pane_current_path}"'
+# old versions
+if-shell "vertest `tmux -V` '<' 1.9" 'bind | split-window -h'
+if-shell "vertest `tmux -V` '<' 1.9" 'bind - split-window'
+if-shell "vertest `tmux -V` '<' 1.9" 'bind _ split-window'
 
 # act like vim
 setw -g mode-keys vi
diff --git a/recipes/default/dotfiles b/recipes/default/dotfiles
index 93f511d..49d754f 100644
--- a/recipes/default/dotfiles
+++ b/recipes/default/dotfiles
@@ -10,3 +10,4 @@ try_link "tmux.conf" "$HOME/.tmux.conf"
 source_dotfile "bashrc"
 source_dotfile "bash_profile"
 source_dotfile "bash_alias"
+source_dotfile "bash_funcs"